Digital Society and Computer Ethics

Digital Society

• Integration of information and communication technologies.
• Impacts home, work, education, and recreation.
• Digital innovations reshaping society, economy, industries.
• Technologies like mobile, cloud, Big Data, IoT transforming various sectors.
• Opportunities for growth, citizen welfare, efficiency.
• Improves health, transportation, energy, agriculture, manufacturing, and more.
• Enhances governance, policy-making, citizen engagement.
• Internet’s potential for democracy, diversity, human rights.
• Need to understand impact on consumers, users, citizens, workers.
• Impact on private life, education, science, government, democracy, business.

Stakeholder of Digital Society

• Society
• Technologies
• Content

Challenges of Digital Society

• Privacy concerns due to increased data collection and surveillance.
• Growing cybersecurity threats and risks of cyberattacks.
• Unequal access to technology and the internet, creating a digital divide.
• Rapid spread of misinformation and false information online.
• Rise of online harassment and cyberbullying.
• Over-reliance on digital interactions leading to social isolation.
• Job displacement caused by automation in certain sectors.
• Health issues arising from digital addiction and excessive screen time.
• Ethical dilemmas posed by AI, automation, and data usage.
• Challenges in regulating the rapidly evolving digital landscape.

Computer Ethics

• Involves moral principles guiding computer use.
• Includes intellectual property rights, privacy, societal impact.
• Ensures ethical implementation and use of computing resources.
• Addresses copyright, trademarks, unauthorized distribution.
• Encompasses human behavior, workplace ethics, compliance.
• Focuses on Internet-related issues like privacy and content publication.

Importance of Computer ethics

• Protect personal and commercial information.
• Control plagiarism, identity fraud, copyrighted material misuse.
• Ensure ICT accessibility for all, including disabled and deprived.
• Prevent dishonest business practices and promote fair competition.
• Promote moral and social values in society.

Concept of Information Security

• More than just preventing unauthorized access.
• Prevents unauthorized access, use, disclosure, disruption, etc.
• Applies to physical and electronic information.
• Encompasses various data types, including personal details.
• Spans research areas like Cryptography, Mobile Computing, etc.

Information Security vs. Cyber Security

• Focus:

• • • Information Security: Primarily concerned with safeguarding data from unauthorized access, disclosure, and modification, ensuring confidentiality, integrity, and availability.
    • Cyber Security: Focuses on protecting computer systems, networks, and digital assets from cyber threats, including attacks and breaches.

• Scope:

• • • Information Security: Encompasses physical and digital data across various forms.
    • Cyber Security: Centers on digital assets, online threats, and vulnerabilities in the cyber realm.

• Components:

• • • Information Security: Involves policies, procedures, access controls, data classification, and risk management.
    • Cyber Security: Includes firewalls, intrusion detection systems, antivirus software, encryption, and incident response.

• Emphasis:

• • • Information Security: Stresses confidentiality, integrity, and availability of information.
    • Cyber Security: Emphasizes protection from cyberattacks, data breaches, and maintaining system functionality.

• Application:

• • • Information Security: Relevant to all aspects of data handling, storage, and transmission.
    • Cyber Security: Specifically addresses online threats and digital systems.

• Examples:

• • • Information Security: Securing physical documents, complying with regulations, data disposal.
    • Cyber Security: Preventing malware infections, DDoS attacks, and unauthorized network access.

• Interconnected:

• • • Both fields are closely related and often overlap due to the digital nature of modern information management.

• Collaboration:

• • • Effective protection often requires collaboration between information security and cyber security experts.

• Evolution:

• • • Both fields evolve to adapt to new technologies and emerging threats in the digital landscape.

• Foundation:

• • The principles of both fields contribute to a comprehensive approach to overall organizational security.

Information security principles

• Basic principles/component of Information Security are CIA:
  

Confidentiality:

• Prevents unauthorized disclosure of information.
• Example: Password seen during login, compromise occurred.
• Breach of confidentiality when unauthorized individuals access information.

Integrity:

• Ensures accuracy and completeness of data.
• Prevents unauthorized editing or tampering.
• Example: Employee leaves, data updated across departments.
• Only authorized personnel are allowed to edit data.

Availability:

• Information accessible when needed.
• Collaboration across organizational teams.
• Example: Checking employee’s leave status.
• Denial of service attacks can disrupt availability.

Information Security Policy

• To prevent and mitigate security breaches.
• To make security policy truly effective.
• To change the company, new threats, conclusions drawn from previous breaches.
• Make information security policy practice and enforceable.

Information security measures

• Technical Measures
• Organizational Measures
• Human Measures
• Physical Measures

Concept of Cybercrime

• Crime committed using network-connected devices.
• Perpetrators called cyber criminals or cyber crooks.
• Growing digitization leads to increased cybercrime.
• Attack computer networks or devices using IT skills.
• Aims: Obtain business information, break accounts, identity theft.
• Include revenge porn, cyber-stalking, harassment, bullying.
• Also involve child sexual exploitation.

Types of Cybercrime:

• Active Attack:

• • • Intended to cause harm or disruption to system or network.
    • Use malicious code, viruses, worms, Trojans, and other forms of malware to carry out active attack
    • Attackers take direct and intentional action that causes harm.

• Passive Attack:

• • • Attacker intercepts and monitors data transmissions without altering or affecting the target system or data.
    • Aims to gather sensitive information, such as passwords, financial data, or confidential communications, without the victim’s knowledge.
    • Designed to be discreet and undetectable, making it challenging for the victim to realize that their data is being compromised.

• Hacking:

• • • Unauthorized access to personal information for illegal gain.
    • Include unauthorized access, data theft, service disruption, and more.
    • Hacking techniques evolve, requiring ongoing security measures to counteract attempts.

• DDoS (Distributed Denial of service) Attacks:

• • • Overwhelm target with traffic to render it inaccessible.
    • Utilize compromised devices in a botnet for traffic generation.
    • Detection involves monitoring traffic patterns and spikes.

• Identity Theft:

• • • Stealing personal information for financial fraud.
    • Unauthorized acquisition and use of someone’s personal information.
    • To assume the victim’s identity for financial gain or fraudulent activities.

• Credit card fraud:

• • • Unauthorized use of credit card information for financial gain.
    • To make fraudulent transactions using stolen card details.
    • Personal data like credit card numbers and CVVs are targeted.

• Cyberstalking:

• • • Harassment or stalking using digital communication and online platforms.
    • Involves persistent and unwanted online attention towards a victim.
    • Uses technology to intimidate, control, and cause fear in victims.

• Cyber extortion:

• • • Demanding money or something of value through online threats or attacks.
    • Impact on victims’ finances, reputation, and operational continuity.
    • Can lead to financial losses, data exposure, and damage to brand image.

• Crypto jacking:

• • • Illegitimate use of others’ computing resources to mine cryptocurrencies.
    • To generate digital currency for the attacker’s benefit.
    • Methods involve infecting devices with malware to mine cryptocurrencies.

• Cyberbullying:

• • • Insulting, harassing, or threatening via the internet.
    • Harassing, intimidating, or targeting individuals using digital communication.
    • Involves repetitive and harmful behavior through online platforms.

• Cyber Espionage:

• • • Covert and unauthorized gathering of sensitive information through digital means.
    • Aim is to obtain valuable data for political, economic, or military advantage.
    • Can lead to compromised diplomatic relations, financial losses, and weakened defense.

• Social Engineering:

• • • Cybercriminals make contact through calls, emails, or in person.
    • Pretend as legitimate entities to gain trust.
    • Aim: Obtain personal and important information.

Malicious Software and Spam

Malicious Software

• Malware stands for malicious software, targeting computers and networks.
• It encompasses harmful programs intended to delete, modify, block, or copy data without authorization.
• Coined by Yisrael Radai in 1990, but examples of malware date back to earlier times.
• One of the earliest instances is the Creeper virus in 1971, an experiment by Robert Thomas.

Different Types of Malware

• Computer Virus:
  • Malicious software that self-replicates and attaches to other files.
  • Activates secretly when the host program is run.
  • Types: Memory-Resident, Program File, Boot Sector, Stealth, Macro, Email Viruses.
• The example of computer virus include
  • Install the operating system, stay in RAM from boot to shutdown.
  • Rare due to modern OS security and Internet precautions.
  • Infects executable files (e.g., .EXE, .COM) to increase chances of execution.
  • Distributed through email messages, activated when attachments or links are interacted with.
  • Encoded as macros embedded in documents, often in applications like Word and Excel.
• Worm:
  • Malicious software that self-replicates like viruses.
  • Automatically executes itself, unlike viruses that need a host program.
  • Spreads over networks quickly, capable of causing substantial damage rapidly.
• Trojan Horse:
  • Non-replicating program.
  • Appears legitimate but contains malicious code.
  • Gains trust and performs harmful activities when executed.
  • Used by hackers for stealing passwords, data destruction, and more.
  • Difficult to detect due to its deceptive nature.
• Logic Bomb:
  • Malicious code triggered by specific events or conditions.
  • Remains dormant until triggered.
  • Used for unauthorized access, data destruction, or harm.
  • Hidden within legitimate software.
  • Difficult to detect until activation.
  • Causes damage or disruption at a specific time/event.
• Zombies:
  • Compromised computers/devices controlled by remote attackers.
  • Part of a botnet network for malicious activities.
  • Used for DDoS attacks, malware spreading, and data theft.
  • Devices include computers, smartphones, IoT devices, etc.
  • Users may not be aware of their devices being used.
  • Prevention requires security measures and updates.
• Phishing:
  • Phishing is a cyberattack that tricks users into revealing sensitive information or performing actions.
  • Attackers use deceptive emails, websites, or messages to appear legitimate.
  • Goals include stealing passwords, financial data, or installing malware.
  • Phishing preys on human psychology and social engineering techniques.
  • Users should be cautious and verify the authenticity of requests before sharing information.
• Spyware:
  • Secretly records user information.
  • Sends collected data to third parties.
  • Information can include accessed files, online activities, and keystrokes.
• Adware:
  • Displays advertising banners during program execution.
  • Can function like spyware, collecting confidential information.
  • Aims to gather data from victim’s computer for various purposes.
• Ransomware:
  • Ransom malware that blocks user access to files/programs.
  • Demands ransom payment through online methods.
  • Paid ransom allows user to regain access to their system
• Rootkit:
  • Malicious software altering OS functionality stealthily.
  • Enables hacker to gain complete control as system administrator.
  • Designed to hide their presence on the victim’s system.
• Botnet:
  • Compromised computer/device networks under remote control.
  • Used for various malicious activities.
  • DDoS attacks, spam distribution, data theft, etc.
  • Infected devices become “bots” or “zombies.”
  • Central control by operators for coordinated attacks.
  • Prevention requires security practices and updates.

• Spam:
  • Unsolicited and often mass emails sent to numerous recipients.
  • Promotes products, services, scams, or fraudulent schemes.
  • Can include email, SEO, social networking, mobile, and messaging spam.
  • Aims to manipulate search results, exploit social platforms, and target mobile users.
  • Clogs inboxes, distracts from legitimate emails, and can be ignorable.
  • Spreads across various digital communication channels.
  • Adverse effects include annoyance, deception, and potential security risks.

Symptoms of Malware attack:

• Unexpected Crashes
• Slow System
• Excessive Hard Drive Activity
• Strange Windows
• Peculiar Messages
• Bad Program Activity
• Random Network Activity
• Erratic Email
• Blacklisting IP Address
• Unexpected Antivirus Disabling

Protection from Cybercrime

• Keep your computer and software updated:

• • • Regularly apply patches and software updates to prevent vulnerabilities.

• Use a non-administrator account whenever possible:

• • • limiting the privileges of the user, reducing the potential impact of security breaches or malicious activities.

• Think twice before clicking links or downloading anything:

• • • When clicking links or downloading files is essential to prevent potential exposure to malware, phishing, and other online threats.

• Be careful about opening email attachments or images:

• • • When opening email attachments or images is important to avoid potential risks of malware infection, phishing attempts, and other malicious activities.

• Don’t trust pop-up windows that ask you to download software:

• • • Being sceptical of pop-up windows that prompt you to download software is important to prevent unwittingly installing malicious or unwanted programs on your device.

• Limit your files-sharing:

• • • Limiting file sharing helps control the exposure of sensitive information and reduces the risk of unauthorized access or sharing of confidential data.

• Use antivirus/antimalware software:

• • • Utilizing antivirus and antimalware software enhances your device’s protection by identifying and mitigating potential threats, ensuring a safer online experience.

• Secure your Network:

• • • To prevent unauthorized access, data breaches, and cyberattacks by implementing strong passwords, encryption, and proper network configuration.

• Backup your Files:

• • • Regularly backing up your files ensures that important data is not lost in case of hardware failure, malware attacks, or other unforeseen events.

• Use Multiple Strong Passwords:

• • • Avoid repeating passwords on different sites.
    • Create complex passwords with letters, numbers, and symbols.
    • Consider using a password management application.

• Keep Your Social Media Accounts Private:

• • • Set privacy settings on social networking profiles.
    • Be cautious about sharing personal information online.

Intellectual Property Right (IPR)

• Legal rights safeguarding intellectual creations like inventions, artistic works, and more.
• Provides exclusive use of intangible assets for a specific period.
• Encompasses copyrights, patents, trademarks, and trade secrets.

Types of Intellectual Property Right

Copyright and related rights:

• Copyright is an IPR that safeguards literary, artistic, and technological creations, including writings, music, fine arts, computer programs, and databases.

Patents:

• Patent is an exclusive right granted to inventors to prevent unauthorized commercial use of their invention for a limited time, in exchange for public disclosure of the invention’s details.

Trademarks:

• Trademark is a distinguishing sign that identifies goods or services of one entity from others. It has historical roots in artisans’ marks and serves to establish brand identity.

Industrial designs:

• Industrial design pertains to the aesthetic aspects of an article, encompassing both three-dimensional features like shape and surface, as well as two-dimensional elements like patterns and colors.

Geographical indications:

• Geographical indications and appellations of origin are signs used on goods with a specific geographical origin, indicating qualities and characteristics linked to that place of origin, often identified by the name of the place.

Trade secrets:

• Trade secrets are confidential and exclusive information such as procedures, systems, formulas, etc., that provide a competitive advantage to a company, contributing to its success.

Why should we promote and protect intellectual property?

• Encourages innovation and creativity.
• Drives economic growth and job creation.
• Preserves cultural heritage and traditional knowledge.
• Ensures fair competition and prevents unauthorized use.
• Attracts investment and foreign direct investment.
• Supports research and development activities.
• Facilitates global collaboration and knowledge sharing.
• Benefits consumers by ensuring product quality and origin.
• Fosters cultural and artistic expression.

Intellectual property rights (IPRs)

• Legal rights protecting intellectual creations.
• Encompass inventions, art, products, and more.
• Types include copyrights, patents, trademarks, trade secrets.
• Encourage innovation, creativity, and economic growth.
• Foster fair competition and prevent unauthorized use.
• Attract investment and support research.
• Preserve cultural heritage and traditional knowledge.
• Ensure product quality and origin for consumers.
• Facilitate global collaboration and partnerships.

Digital Signature

• Electronic form of signature to authenticate sender’s identity or document signer.
• Ensures original content integrity and prevents tampering.
• Transportable and not easily imitated.
• Provides non-repudiation, authentication, and message integrity.
• The Government of Nepal adopted digital signatures officially on December 2, 2015.
• Utilizes cryptographic measures for authenticity, non-repudiation, and integrity.

Working mechanism of digital signature

• Two keys are generated : Private key and Public key.
• Private key kept by signer and kept securely.
• Public key owned by the receiver to decrypt the message.

Hash function:

• Hash function generates a fixed-length string from data using a mathematical algorithm.
• It works for files of any size, like emails, documents, or images.
• The generated hash is unique to the input data.
• Hashing is a one-way process; you can’t reverse it to find the original data.
• Even a small change in input data produces a significantly different hash.
• Used in data integrity verification, password storage, digital signatures, etc.

Public Key Infrastructure (PKI):

• PKI facilitates digital signatures and more.
• It involves a private-public key pair for each transaction.
• Private key is kept secret and used for signing.
• Public key is used for validating signatures.
• Ensures secure key generation, usage, and storage.
• Involves a trusted Certificate Authority (CA).

Certificate Authority (CA):

• Digital signatures rely on public-private key pairs.
• Assurance of secure key creation and usage is vital.
• CAs are trusted third-party organizations.
• CAs ensure key security and provide digital certificates.
• CAs validate identities before issuing certificates.
• Digital certificates are digitally signed by CAs.

Digital Certificate:

• Issued by a Certificate Authority (CA).
• Contains public key and associated identity.
• Used to confirm the key’s ownership.
• CA acts as a guarantor of authenticity.
• Valid for a specified time.
• Necessary for creating a digital signature.

Advantage and Disadvantages of Digital Signature:

Advantage of Digital Signature: 

1. Enhanced security and resistance to forgery.
2. Authenticates sender’s identity.
3. Ensures data integrity.
4. Provides non-repudiation.
5. Saves costs and time.
6. Increases efficiency in workflows.
7. Globally accepted for legal purposes.
8. Positive environmental impact.
9. Simplifies audit trail creation.
10. Integrates well with digital workflows.

Disadvantage of Digital Signature: 

1. Dependence on technology and digital infrastructure.
2. Complex implementation and management.
3. Key management challenges.
4. Variability in legal recognition.
5. Infrastructure requirements for both parties.
6. Initial costs for implementation.
7. User acceptance and familiarity concerns.
8. Potential for misuse or fraudulent activities.
9. Complex revocation processes.
10. Risk of sensitive data exposure during transfer.

Cyber Law in Nepal

• Governs legal matters related to computers, internet, data, software, and networks.
• Encompasses legal issues in cyberspace.
• Pertains to preventing internet-related crimes.

Area of Cyber Law

1. Electronic and Digital Signature:
2. Computer Crime:
3. Intellectual Property:
4. Data Protection and Privacy:
5. Telecommunication Laws:

Cyber law in Nepal

• Cyber Law covers diverse issues tied to the internet and technology.
• Encompasses intellectual property, privacy, expression, and jurisdiction.
• Nepal’s first cyber law is the Electronic Transaction Act, 2063.
• Responds to the increasing internet use in Nepal.
• Addresses commercial, private sector, and criminal aspects.
• Covers digital signatures, intellectual property, and cybercrime.
• Consists of 12 sections and 80 clauses.
• Focuses on computer networks and cybercrime.
• Brings cybercriminals to court and imposes penalties like other crimes.

Provisions included in the laws:

• Comprehensive coverage of cyber activities.
• Key legislation for Nepal’s IT industry development.
• Criminal and civil consequences for hacking, data theft, and more.
• Penalties include imprisonment up to 5 years or fines.
• Focus on severity and repetition of the crime.
• Enhanced security for electronic banking transactions.
• Boosts economic activities over the internet in Nepal.
• Legal recognition for government websites and digital signatures.
• Applies to e-banking, e-commerce, and more electronic media.

 ICT Policy in Nepal

• ICTs are essential for sustainable development and economic growth worldwide.
• They transform social interactions and public service delivery.
• Nepal considers ICTs crucial for poverty reduction and development goals.
• Efficiency is a key indicator of competitiveness, and ICTs contribute to efficiency.
• ICTs play a role in better governance, education access, healthcare outreach, and economic growth.
• Challenges arise from the fast-paced nature of ICT innovation and evolving policy needs.
• Policy formulation needs to adapt to technological trends, including cybersecurity, data protection, privacy, and intellectual property rights.
• Addressing challenges of technological convergence and regulatory governance is important.
• As telecom connectivity expands, focus shifts to strengthening demand-side fundamentals.
• ICTs offer a tool to bridge development gaps and improve citizens’ quality of life.

Vision

• Goal to transform Nepal into an information and knowledge-based society and economy.

Mission

• To create conditions for the intensified development and growth of ICT sector as a key driver for
• Nepal’s sustainable development and poverty reduction

Major Objectives

• Make ICT accessible and affordable to all citizens.
• Develop and expand ICT infrastructure.
• To promote good governance through the use of ICT.
• Achieve sustainable and inclusive socio-economic development through the use of ICT
• Create the opportunities of human resources development through the use of ICT.

Policy:

• Promote a stable, fair and competitive investment climate.
• Facilitate the development of e-Trade and E-Commerce activities.
• Enhance competitiveness of farmers through ICT in agriculture.
• Improve communication systems for tourism development.
• Support e-Government planning and strategies.
• Develop ICT services to bridge the digital divide.
• Ensure efficient use of ICT infrastructure for resilience.
• Enhance institutional capacity for ICT education in educational institutions.
• Increase enrollment and output of students in key ICT-related skills.
• Deploy ICTs in education for better outcomes and expanded access.
• Facilitate youth and women’s participation in ICT, media, and content development.
• Address gender-based inequalities in ICT initiatives.
• Promote use of free and open source software in government.
• Develop a competitive and regulated ICT industry through innovation and partnership.
• Attract ICT-related foreign investments, especially in the IT-ITES/BPO sector.
• Utilized ICT for social and economic development.
• Expand broadband services through national telecommunications infrastructure.
• Utilize regional and international telecom infrastructure for economic integration.
• Safeguard public sector information and investments from negative ICT impacts.
• Facilitate e-Trade and E-Commerce with a stable investment climate.

 Introduction to Multimedia

• Combines text, graphics, audio, and video on computers.
• Enables navigation, interaction, creation, and communication.
• Offers various ways to communicate information.
• TV, animated films, radio broadcasts use different media.
• Multimedia employs sound, video, graphics, animation.
• Unimedium uses a single medium (e.g., text-only book).

Benefits of Multimedia:

• Enhances comprehension using multiple senses.
• Illustrative diagrams improve understanding.

Interactive Multimedia

• Involves a combination of various media formats.
• Utilizes different forms of communication and interaction.
• Enhances user engagement and interactivity.
• Commonly used in entertainment, education, and communication.
• Utilizes technology to blend text, graphics, audio, video, and animations.
• Aims to provide a rich and immersive user experience.

Category of Multimedia

• Divided into five categories: Text, Graphics, Audio, Video, and Animation.
• Each category represents a specific type of media content.
• Allows for versatile and engaging content creation.
• Enables a comprehensive and dynamic communication approach.
• Combined to create interactive and immersive multimedia experiences.

Component of Multimedia

Text:

• Fundamental and effective for communication.
• Used as headlines, subtitles, and slogans.
• Expresses specific information or reinforces other media.
• Includes text types, sizes, colors, and backgrounds.
• Sets tone, image, mood through font and colors.
• Enhances message understanding and accessibility.
• Provides alternatives when images aren’t available.
• Enables access to other media via text links.

Graphics or image:

• Crucial due to human visual orientation.
• Include images, photos, illustrations, icons, etc.
• Non-moving elements that complement text.
• Illustrate points and ideas alongside text.
• Go beyond decoration; integral in multimedia.
• Graphics include slide shows, galleries.
• Clickable graphics lead to other elements.
• Enhance communication through visual impact.

Audio:

• Enhances website and social media design.
• Uses dialogue, narration, music, sound effects.
• Audio elements catch attention and focus.
• Delivers information effectively.
• Reinforces visitor’s comprehension.
• Moderation is important.
• Narration explains animations.
• Music and effects enhance experience.

Video:

• Combines images and sound for moving pictures.
• Powerful impact on websites and social media.
• Diverse applications: inform, spread the word, educate.
• Showcasing products, building brand awareness.
• Popular on social media platforms like Facebook, Twitter, LinkedIn.
• Short videos offer marketing advantage.
• Effective for differentiation and engagement.

Animation:

• Animation is a series of images for movement.
• Common in multimedia applications.
• Includes 2D and 3D digital animation.
• Illustrates concepts involving movement.
• Adds visual interest, highlights information.
• Explains processes or entertains.
• Can be interactive with mouse and keyboard.
• Dynamic content within a single container.
• A powerful communication tool.

Hypermedia:

• Hypermedia expands on hypertext, allowing users to click on text links, images, movies, graphics, and other media.
• This enables navigation to different web pages.
• Image links are a common form of hypermedia, connecting visual elements to other pages.

Advantage of Multimedia:

• User-friendly and energy-efficient.
• Engages multiple senses (hearing, seeing, talking).
• Integration and interactivity through digitization.
• Easy feedback enhances interaction.
• Flexibility for different situations and audiences.
• Applicable to individuals and groups.
• Useful for web page creation.
• Enables distance education and video conferencing.

Disadvantage of Multimedia:

• Information overload: Can present too much information at once.
• Compilation time: Takes time to create the original draft.
• Cost: Utilizing various resources can be expensive.
• Practicality: Large files (video, audio) affect loading times.
• Limited distribution: Accessibility issues in remote or poor areas.

Application of Multimedia

1) Education:

• • • Education is a human right for all.
    • Challenges like geography, technology, lack of higher education options.
    • Distance education options available: CBT (CD-based) and WBT (Web-based).
    • CBT offers CD-based courses, while WBT provides online courses.
    • Smart education tools in schools and colleges for interactive learning.
    • Many universities offer online degrees and distance education.
    • Learning becomes engaging and enjoyable.

2) Entertainment and Games:

1. 1. • Education is a human right for all.
      • Challenges like geography, technology, lack of higher education options.
      • Distance education options available: CBT (CD-based) and WBT (Web-based).
      • CBT offers CD-based courses, while WBT provides online courses.
      • Smart education tools in schools and colleges for interactive learning.
      • Many universities offer online degrees and distance education.
      • Learning becomes engaging and enjoyable.

3) Business:

1. 1. • Includes product demos, instant messaging.
      • Voice and live conferencing are excellent applications.
      • Engages audiences and widely used in programs.
      • Mechanics and various professionals can benefit.
      • Easy-to-use authoring tools for program creation.
      • Applications enhance smooth and effective operations.

4) Communication:

1. 1. • Multimedia tools allow cost-effective communication via live text, audio, and video chats.
      • This enhances daily communication’s ease, efficiency, and effectiveness.
      • Interactive multimedia-based social networking platforms like Facebook, Twitter, and Hi5 make communication faster across different time zones.
      • Communication through these platforms comes at a nominal cost.

5) Training:

1. 1. • Various systems available for training students.
      • Covers subjects from mathematics to complex medical procedures.
      • Incorporates audio clips and multi-angled views for practical skills.
      • Equipped with decision-making utilities for personalized training.
      • Uses video sequences to clarify concepts.

6) Web Page Designing:

1. 1. • Websites today serve as information sources for organizations and individuals.
      • Multimedia tools like images, audios, videos, and animations are used to interactively share information with users.
      • This approach enhances clarity in delivering information to recipients.
      • Various types of websites, such as news, educational, medical, business, and personal sites, adopt dynamic layouts for attractive and engaging web pages.

7) Journalism:

1. 1. • Modern journalists have expanded roles, including reporting, photography, editing, interpretation, and design.
      • Proficiency in multimedia tools is crucial for effectively designing and editing news articles.
      • Journalists gather diverse field footage to create captivating audio and visual content.
      • This multimedia approach ensures easy global accessibility to news content.

8) Engineering:

1. 1. • Software engineers frequently employ multimedia tools for tasks like computer graphics, simulations, and product demonstrations.
      • These tools have versatile applications, spanning scientific research to entertainment design.
      • Utilizing multimedia tools yields productive results for business entrepreneurs.
      • The impact of such usage extends to future societal implications.

9) Advertising:

1. 1. • Internet’s rise changed advertising.
      • Multimedia is crucial in advertising.
      • Used in both print and electronic ads.
      • Created using professional software.
      • Presents to target audiences effectively.

10) Virtual Reality:

1. 1. • Enables user interaction with computer-simulated environments.
      • Environment can mimic the real world or be completely different.
      • Used in training (pilot, combat, surgery) and games.
      • Built on multimedia technology.

11) Medicine:

• • •  Doctors trained with virtual surgery and disease simulations.
    • Develop techniques to prevent virus and bacteria spread.
    • Multimedia aids practical training and skill development.

Introduction to Web Development

Webpage and Website

Webpages:

• Digital document on the World Wide Web.
• Written in languages like HTML, CSS, JavaScript.
• Contains text, images, videos, links, and more.
• Delivers information, media, and functionality.
• Retrieved from a web server using a URL.
• Accessed through browsers via URLs.
• Contains text, graphics, and hyperlinks.
• Can be static (unchanging) or dynamic (changing content).
• Dynamic pages use scripting languages like PHP, Perl, ASP, JSP.
• Scripts on server generate content like date, time, and database info.
• Content returned as HTML code.
• Browsers translate HTML for display.

Websites:

• Collections of interconnected web pages.
• Hosted on a single domain or web address.
• Accessed through web browsers.
• Provide information, resources, and services.
• Created using HTML, CSS, JavaScript.
• Can include multimedia elements.
• Accessed via URLs in web browsers.
• Collection of interconnected web pages.
• Grouped together and linked.
• Referred to as “web site” or “site.”
• Created by individuals, groups, businesses, or organizations.
• Serve various purposes and functions.
• Accessed through web browsers.
• Enter URL in browser’s address bar to visit a site.
• Search engines help find websites.

Web Browsers and Search Engines

• Software for locating, retrieving, and displaying web content.
• Enables access to web pages, images, videos, and files on the World Wide Web.
• Allows users to enter website addresses and browse the internet.
• Essential for accessing websites and online content.
• Early browsers like Mosaic and Netscape Navigator rendered HTML and supported bookmarks.
• Modern browsers handle HTML, JavaScript, AJAX, multimedia, and more.
• Many browsers offer extensions and plugins for added functionality.
• Examples include Google Chrome, Mozilla Firefox, Apple Safari, Microsoft Edge, Internet Explorer.

Web Development Process

• Planning and Requirement Analysis:

• • • Define the purpose, goals, and target audience of the website.
    • Gather requirements, features, and functionalities.

• Design:
  • • Create wireframes or mockups outlining the layout and structure.

• • • Design the user interface (UI), including colors, typography, and visual elements.

• Development:

• • • Write HTML, CSS, and sometimes JavaScript code to create the user interface.
    • Ensure responsiveness for various devices and screen sizes.
    • Develop the server-side logic and databases.
    • Implement functionality, data processing, and interactions.

• Integration:

• • • Combine the front-end and back-end components.
    • Test for compatibility and data flow between both ends.

• Testing Deployment:

• • • Perform comprehensive testing, including functionality, usability, performance, and security.
    • Identify and fix bugs and issues.
    • Upload the website to a web server or hosting platform.
    • Configure domain, server settings, and databases.

• Launch:

• • • Make the website live and accessible to the public.
    • Monitor for any issues that might arise after launch.

Overview of Various Internet & Web Technologies

Overview of Internet

• Global network of interconnected computers.
• Allows communication and sharing of information worldwide.
• Built on a decentralized architecture.
• Uses standardized protocols like TCP/IP.
• Enables access to websites, email, file sharing, and more.
• Originated from ARPANET in the 1960s.
• Internet Service Providers (ISPs) provide access.
• Web browsers are used to access web content.
• Facilitates online communication, commerce, and collaboration.
• Continuously evolving with new technologies and services.

Uses of Internet

• Communication
• Information Access
• Education
• Entertainment
• E-Commerce
• Research
• Work and Business
• Social Networking
• Banking and Finance
• Healthcare

Misuses of Internet

• Copyright Infringement
• Cyber Crime
• Hate Speech
• Spread of Misinformation

Web Technology

• Refers to technology operating on the World Wide Web.
• Enables businesses to enhance tasks and databases with mobility.
• Accessible from any location through the Internet.
• Also known as SaaS (Software as a Service).
• Paid based on usage, no software installation required.
• Accessible via simple signup and browser URL.
• Example: Configuring devices through a web-based console.
• Includes mark-up languages (HTML, CSS, XML), CGI, JavaScript, and HTTP.
• Encompasses programming languages, web servers, databases, and business applications.

Protocol

• Set of rules for data transmission.
• Governs communication between devices/systems.
• Defines format, order, and timing of messages.
• Enables effective and standardized interaction.
• Essential for networks, telecommunications, software applications.

URL

• Uniform Resource Locator (URL).
• Used to locate resources on the internet.
• Includes protocol, domain/IP, and path to the resource.
• Standardized way to access web content and files.

Domain Name System

• Hierarchical system.
• Translates domain names to IP addresses.
• Enables user-friendly web addressing.
• Facilitates internet resource access.

Email

• Digital messages sent over the internet.
• Include text, images, attachments, links.
• Use protocols like SMTP, POP3/IMAP.
• Sent, received, and organized via email clients or webmail services.
• Types of Email: Email Client, Webmail.

Content Management System (CMS)

Introduction

• Stands for Content Management System.
• Manages content using a database.
• Used for website development.
• Updates content and structure.
• Often open-source and free.
• May offer paid options like templates and plugins.
• Example: WordPress, Wix, Web flow, Tumblr, etc
• Content Management Application (CMA), Content Delivery Application (CDA) are two parts of CMS.

Feature of CMS:

• User Management: Manage user roles and information.
• Theme System: Modify site appearance and functionality.
• Extending Plugins: Add custom features using plugins.
• Search Engine Optimization (SEO): Built-in SEO tools.
• Media Management: Organized and upload media files.
• Multilingual: Supports content translation.

HTML the Language of the Web

• Scripting language for creating hypertext documents on the web.
• Invented by Tim Berners-Lee around 1990.
• Based on SGML (Standard Generalized Markup Language).
• Later evolved into XHTML (Extensible Markup Language) by W3C.
• Uses tags to define structure and presentation of content.
• Platform-independent, works on various operating systems.
• Browsers interpret HTML tags to display content.
• Provides tags for graphics, fonts, colors, and hyperlinks.
• Versions include HTML 1.0 (1990), HTML 2.0 (1995), HTML 4.0 (1998), XHTML (2000), HTML 4 (2014).

Objectives of HTML:

1. Create web pages for websites.
2. Essential markup language for web pages.
3. Allows adding graphical elements like videos, images, rich text.
4. Facilitates customization with HTML5 and newer versions.
5. Learn coding tools: code editor and browser developer tools.
6. Create hypertext links to various online resources.

 Structure of HTML:

• Divided into two parts: the head and the body.
• Start with the declaration: ‘<!DOCTYPE html>’.
• Four primary container tags: ‘<html>’, ‘<head>’, ‘<title>’, and ‘<body>’.
• Tags must appear as pairs with both opening and closing tags.

Published and Hosting (Web Publishing and Web Hosting)

Web Publishing:

• Process of sharing content on the internet.
• Involves creating websites, updating pages, and posting blogs.
• Content includes text, images, videos, and more.
• Requires web development software, internet connection, and web server.
• Software can be professional tools or web-based interfaces.
• Internet connection is needed for uploading content to servers.

Web hosting:

• Web hosting can be dedicated or shared.
• Web publishing is cost-effective, as it doesn’t require physical materials.
• Offers a global audience accessible through an internet connection.
• Service for posting websites on the internet.
• Web host provides technologies for website viewing.
• Websites are stored on servers.
• Users access websites by typing the domain in their browser.
• Domain ownership often required for hosting.
• Choose a reliable web host with good support and minimal downtime.
• Pay a monthly fee based on disk space and bandwidth needs.
• Estimate site size and traffic before signing up for hosting.

 HTML Tags vs. Attributes

• Definition of a tag: Group of characters surrounded by ‘<‘ and ‘>’.
• Tag sections: Name, attributes, attribute value.
• Tag name: Unique identifier.
• Attributes: Tag properties, diverse attribute values.
• Example: <body> tag, bgcolor attribute with value green.
• Two tag types: Single tag, Pair tag.

Basic Tags of HTML

• <html> tag
  • Marks the start and end of an HTML document.

• <head> tag
  • Contains document title and general information (author, copyright, keywords, description).

• <body > tag

• • Defines webpage content displayed in the browser.
  • Allows use of various HTML tags.
  • Common attributes of <body> tags are:

• • Color code format: “#rrggbb”.
  • rr for red, gg for green, bb for blue.
  • Values range from 00 to ff in hexadecimal

• <meta> tag

• • ‘<meta>’ tag provides metadata about the HTML document.
  • Includes information like character encoding, author, viewport settings, etc.
  • Often placed within the ‘<head>’ section of the document.

Heading Tag (H1 to H6) and Attributes (ALIGN)

Heading Tags

• Six levels: ‘<h1>’ to ‘<h6>’.
• Importance increases from ‘<h1>’ to ‘<h6>’.
• Default display: larger and bolder font.
• ‘<h1>’ is most important, ‘<h6>’ is least important.
• Font size decreases from ‘<h1>’ to ‘<h6>’.

Font Tag and Attributes (Sizes: 1 to 7 Levels, BASEFONT, SMALL, BIG, COLOR)

<font> Tag

• Sets font properties: color, face, size.
• Default font size is 3.
• Default color is red.
• Default font face is Times New Roman.

<basefont> Tag

• Default font size is three.
• Modify default size with <basefont> tag.
• Use “size” attribute to specify font size.
• No closing tag for <basefont>.

Paragraph Formatting (P)

<p> Tag

• Marks a block of text as a paragraph.
• Adds space between paragraphs in a webpage.

Break Line BR

<br> Tag and <hr> Tag

• ‘<br>’ tag: Empty element to break a line without space.
• ‘<hr>’ tag: Insert horizontal rule to visually separate content.
• ‘<hr>’ is a single tag.

Comment in HTML (<! >)

Comment Tag and Space Character

• Start with ‘<!’ and end with ‘>’.
• Can span multiple lines.
• Can be placed anywhere in the document.
• Contents not displayed in browsers.

 Formatting Text (B, I, U, Mark, Sup, Sub, EM, BLOCKQUOTE, PREFORMATTED)

General Text Formatting

• Utilize tags like bold, italic, underline, font, paragraph, heading, etc.
• Basic formatting elements for text.
• <br> tag creates line breaks.

<marquee> Tag and <pre>

• <marquee> tag:
  • Creates simple text animations.
  • Attributes include direction, behavior, width, bgcolor, scrollamount.
• <pre> tag:
  • Maintains formatting from text editor.
  • Displays HTML code as it’s written.

Special Characters

Ordered List- OL (LI, Type- 1, I, A, a; START, VALUE)

List

• Uses numbers for list items.
• Defined by <ol> and </ol> pair tags.
• Attributes and values can be specified.
• Attributes include “type” and “start”.

Unordered List – UL (Bullet Type- Disc, Circle, Square, DL, DT, DD)

• Uses bullets for list items.
• Supported bullet types: disc, circle, square.
• Defined by ‘<ul>’ and ‘</ul>’ pair tags.

Definition List

• Represents term and description pairs.
• Starts and ends with ‘<dl>’ and ‘</dl>’.
• Terms enclosed with ‘<dt>’.
• Descriptions enclosed with ‘<dd>’.
• Can also be used to create dialogues.

ADDRESS Tag

• ‘<address>’ tag in HTML shows contact info of a person/organization.
• In ‘<body>’, it’s document contact info; in ‘<article>’, it’s article contact info.
• Text inside ‘<address>’ appears in italic.
• Browsers may add line breaks before and after the ‘<address>’ element.

Inserting Image:

• ‘<img>’ tag inserts images in web pages.
• It’s a pair tag.
• Browsers display limited image types: GIF, JPG, and some support PNG.
• GIF and JPG are widely supported; modern browsers handle PNG.
• JPG is ideal for high quality, compression, and color variety.
• JPG format offers attributes and values for customization.

Inserting Object:

• Objects are external files like pictures, audio, video, etc.
• Plug-ins enhance browser functionality (Java, Flash, etc.).
• <embed> tag for external applications; <object> tag for embedded objects.
• Use <img> for pictures, <video> and <audio> for multimedia.
• For embedding webpages, use <iframe> tag.

Anchor Tag and Hyperlink

Creating Hyperlink

• Created using <a> tag in HTML.
• Defined by the “href” attribute.
• Links between files, webpages, images, emails, etc.
• Enables navigation between different web content.
• Open the linked page in the current browser window.
• “target” attribute with “_blank” value opens in a new window.

Links to place in other HTML documents

• Create the link to the target file.
• Downloaded when the user clicked using attribute download.
• Changed the hyperlink color by using <body> tag
• Unvisited hyperlink text appears as blue color, visited hyperlink as purple color.

Image Map

• <map> tag creates clickable areas on images.
• “name” attribute specifies the image map’s name.
• “usemap” attribute in <img> links to the <map> tag.
• <area> tag defines clickable regions on the image.
• “shape” attribute determines the shape of the clickable area.
• “coords” attribute specifies the coordinates of the shape.

Table: Creating Table using TH, TR and TD tags

Creating Table 

• <table> tag defines a collection of rows and columns.
• <tr> tag defines a table row.
• <td> tag defines table data within a row.
• <th> tag defines table headers within a row.
• Optional <caption> tag for table captions.

Form: Creating form using Textbox, Radio, Checkbox, Text Area, Button

Creating Form

• Form allows users to enter data on webpages.
• Data is sent to the server for processing or storage.
• Various form elements based on input types.
• Elements have different attributes.
• Form defined by <form> tag.
• Form elements include <input>, <textarea>, <button>, <select>, <option>, <optgroup>, <fieldset>, and <label> tags.

<label>Tag

• Specifies a label for form elements like <input>, <select>, etc.
• Recommended in HTML5 for better coding practice.
• Has attributes: “for” and “form”.
• “for” attribute links to the element’s “id”.
• Ensures alignment between <label> and <input> tags.

Creating Frameset

• Divides a window into sections.
• Embeds multiple webpages as frames.
• <FRAMESET> tag defines frames with “cols” and “rows”.
• “cols” and “rows” define column and row proportions.
• <frame> tag inserts webpages into frames.
• “src” attribute specifies source file or URL.
• No <BODY> in the file containing <FRAMESET>.

Introduction to HTML5 Elements including Audio, Embed, Source, Track and Video Attributes

Introduction to HTML5

• Fifth and newest version of HTML standard.
• Introduces rich media support and improved web application interaction.
• Features new multimedia tags ‘<audio>’ and ‘<video>’.
• Includes vector graphics and new semantic elements.
• Supports Drag and Drop functionality.
• Offers geo-location services.
• Provides web storage for offline data.
• Utilizes SQL database for offline data storage.
• Allows drawing various shapes.
• Handles incorrect syntax effectively.
• Simple DOCTYPE declaration: ‘<!doctype html>’.
• Easy character encoding with ‘<meta charset=”UTF-8″>’.

HTML5 Graphics using canvas and svg Tags

<canvas> Tag

• Used for drawing graphics on a webpage.
• Provides a transparent drawing area.
• Useful with JavaScript and styles.
• Attributes: “id” for unique name, “height” for canvas height in pixels, “width” for canvas width in pixels.

<svg> Tag

• Uses XML format.
• Defines vector graphics like circles, rectangles, polygons.
• Container for elements like <circle>, <rect>, <polygon>, etc.
• Used for drawing scalable graphics on web pages.

Structure of HTML5

• <main>, <section>, <article>, <header>, <footer>, <aside>, <nav>, <figure>.
• Organizes web content efficiently.
• Aids in content management and search optimization.

Concept of Domain Name and Web Hosting

Domain  Name System 

• Website address on the internet.
• Users access websites through domain names.
• Identifies computers using IP addresses.
• Easier to remember than numerical IP addresses.
• Limited to 63-character maximum, 1-character minimum.
• Follows protocol in the URL.
• Combination of letters and numbers with extensions like .com.
• Requires registration before use.
• Unique for each website.
• Ensures visitors reach the intended website.

Web hosting

• Web hosting involves posting websites on servers provided by hosting companies.
• Websites can be accessed on the Internet by entering their domain in a browser.
• Hosting requires owning a domain, which can be acquired through the hosting company.
• Choose a web hosting service with good technical support and minimal downtime.
• Monthly fees depend on site size and bandwidth usage.
• Estimate site size and expected traffic before selecting a hosting plan.

Types of web hosting

• Shared Web Hosting
• Reseller Hosting:
• Dedicated Hosting
• Managed Hosting

Cascading Style Sheet

Introduction to Cascading Style Sheet (CSS)

• Stands for “Cascading Style Sheet.”
• Used to format web page layout.
• Defines text styles, table sizes, and more.
• Creates uniform look across multiple web pages.
• Styles defined once in a CSS document.
• Easily change styles across pages by modifying the CSS.
• Formats text, table cells, borders, images, and layout.
• Provides precise control over web page appearance.
• Often used in combination with HTML for modern web design.

 Inline CSS

• Style defined using “style” attribute.
• Applied directly to HTML elements or tags.

Embedded CSS (Internal Style)

• Defined using <style> tag in the <head>.
• Applies styles to the HTML file only.
• Not visible outside the HTML file.

 External CSS

• Uses separate .css files for styling.
• Ideal for managing many HTML attributes.
• Eliminates need to rewrite CSS in every HTML.
• Created by writing code in Notepad and saving as .css or directly in Visual Studio.

Some More on CSS

Class Style

• More flexible method
• A dot (.) operator is used
• Implemented on two way: element specific style and universal style

</html>

• Universal style starts with a dot (.) operator.
• Used any tag like: heading, paragraph, font, etc

<span>Tag

• Inline container used to highlight or mark a line of a text.
• Using test related attributes within any tags such as font, paragraph, etc

Programming Concept

Computer Program

• Set of instructions for specific tasks.
• Written in programming language.
• Compiled to machine code or interpreted.
• Software includes programs, libraries, data.

Characteristics of a Good Computer Program:

• Portability: Runs on different platforms with minimal changes.
• Readability: Clear logic, easy for programmers to understand.
• Efficiency: Uses processing time and memory effectively.
• Structural: Divides tasks into independent subtasks.
• Flexibility: Handles changes without full rewrite.
• Machine Independence: Runs on different systems.
• Cost Effectiveness: Measures overall cost and human effort.

Introduction to Programming Language

• Designing, writing, testing, and maintaining code.
• Creating instructions for computers to interpret and execute.
• Developing software applications, websites, games, etc.
• Involves algorithms, logic, and commands for specific tasks.
• Language used by human is natural language, and language used by computer is programming language or computer language.
• Writing a program is known as programming or coding.
• Formal system for communicating instructions to computers.
• Intermediary between human understanding and machine execution.
• Enables software creation through written code.
• Wide range of syntax, features, and paradigms.
• Example of programming language are:
  • Python
  • Java
  • C/C#
  • C++
  • Ruby
  • JavaScript, etc.

 Low level, High level, 4 GL Programming Language (Types of Programming Language)

• Classified to two Categories: High Level and Low Level Language.
• Internally using language by computer itself is low level language
• Mathematical expression and structure close to English is a high level language.

1. Low Level Language

• Close to machine codes (0s and 1s).
• Programs in binary form.
• Requires hardware-specific knowledge.
• Classified into two groups:

a) Machine Language

• Uses 0s and 1s, readable by hardware.
• Consists of Operation code and Operand.
  • Directly readable by CPU, speedy processing.
  • Prone to human errors due to binary representation.
  • Detecting/correcting errors is challenging and time-consuming.
• Merit of Machine Language:
  1. Directly understands by CPU.
  2. It takes less time to execution.

  Demerit of Machine Language:

  1. Machine dependent.
  2. Difficult to program
  3. Difficult to modify
  4. Hardware knowledge required.
  5. Difficult to find out the errors.

b) Assembly Language

• Closest to machine language, uses alphabets and numbers.
• Uses MNEMONIC codes for instructions.
• Assembler translates symbolic code to machine instructions.
• Source code written in symbolic language.
• Object code generated by the assembler.
• Examples: CLA (Clear and Add), STA (Store), ADD, SUB.
• Easier than machine language, yet cumbersome.
• Error detection and fixing is easier than machine code.
• Still more challenging than high-level languages.

Merit of Assembly Language:

1. Easier to understand and use than machine language.
2. Easier to locate and remove the errors.
3. It is easier to modify.
4. It is easy to re-locatable.

Demerit of Assembly Language:

1. It is machine dependent.
2. Detailed knowledge of hardware is required.
3. It uses machine level coding.
4. Language processor (Assembler) is required to translate the coding.

2. High Level Language

• Closer to human language, it follows syntax rules.
• Converted to machine-readable format.
• Source code in high-level language.
• Object code after conversion.
• Compilation done by compiler/interpreter.
• High-level languages are usually machine independent.
• Easier to learn and faster to write than symbolic.
• Better documentation and easier maintenance.

Merit of High level language:

1. Machine independent.
2. Easy to write and learn then low level language.
3. Easy to find out and remove the mistakes.
4. High level programs are easy to maintain.
5. Better documentation.

Demerit of High level language:

1. Execute very slowly.
2. Need language processor (Compiler, Interpreter) to translate the program.
3. Some programs cannot be solved with these languages.
4. Lower efficiency.
5. Less flexibility.

a) Third Generation Language (3GL)

• Procedure-oriented for solution steps.
• Sequential instructions needed.
• Vocabulary: keywords and symbols.
• Programs written using words, symbols, rules.
• Also known as Procedure-oriented Languages

Merit of third generation language are:

1. English-like statements, user-friendly.
2. Faster program development.
3. Ease of understanding and modification.
4. Simple syntax error detection and debugging.
5. Standardized and machine-independent.
6. Examples: C, COBOL, FORTRAN, PASCAL, etc.

Demerit of third generation language are:

1. Complexity for beginners
2. Learning curve
3. Hardware dependency
4. Limited abstraction
5. Efficiency concerns
6. Challenging debugging
7. Less control over hardware
8. Limited portability
9. Performance trade-offs

b) Fourth Generation Language (4GL)

• Closer to natural language than 3GLs.
• No detailed step-by-step instructions.
• Descriptive approach for results.
• Often database-oriented.
• Users can create own applications.
• English-like syntax.
• Examples: SQL PLUS, HTML, PHP.
• Application-specific and problem-solving.
• Known as Problem-oriented Languages.

Merit of fourth generation language are :

1. No need to know machine details.
2. Variety of languages available.
3. Easy bug detection and debugging.
4. English-like syntax, user-friendly.
5. Faster and easier coding.
6. Supports OOP and code reusability.

Demerit of fourth generation language are :

1. Needs a compiler/interpreter for conversion.
2. Conversion and execution time.
3. Less efficiency than machine language.
4. Inefficient resource usage.

Difference between 3GLs and 4GLs

c) Fifth Generation Language (5GL)

• Known as Natural language, artificial language.
• Natural languages: Human languages like Nepali, English.
• Artificial languages: C, C++, Java, used by computers.
• Fifth generation computers: Aim to understand human languages.
• Fifth generation language: For natural interaction, AI, neural networks, expert systems.
• LISP and PROLOG: Examples of present-day natural languages.

Merit of fifth generation language are:

1. Ease of Use
2. Wide Adoption
3. Rich Expression
4. Contextual Understanding
5. Flexibility
6. Inclusivity
7. Cognitive Load Reduction
8. Natural Interaction
9. Efficiency for Certain Tasks
10. Communication with Non-Programmers

Demerit of fifth generation language are: 

1. Complexity
2. Limited Precision
3. Learning Curve
4. Performance Overhead
5. Dependency on AI
6. Resource Intensive
7. Potential Ambiguity
8. Limited Optimization
9. Compatibility
10. Reliance on Infrastructure

Compiler, Interpreter and Assembler (Language Translator)

• Language translator: Converts text or speech between languages.
• Maintains meaning and context.
• Bridges language barriers in various areas like business, travel, etc.
• Human or machine-based translation.
• Enables effective cross-cultural communication.

Assembler

• Translates assembly language to machine language.
• Takes assembly language program as input.
• Produces machine language program as output.
• Converts human-readable code to binary.
• Essential for programming in low-level languages.

Interpreter

• Translate one line at a time.
• Execute each line immediately.
• No object program generated.
• Slower and less efficient.
• Suitable for testing and learning.
• Ideal for logical correctness checks.
• Compilation is postponed.
• Beneficial for beginners and learners.

Compiler

• Translates high-level programs to machine codes.
• Converts entire programs, not just single statements.
• Source program becomes object program.
• Errors must be fixed before translation.
• Specific to the language it’s designed for.
• Different compilers for different languages.
• Produces binary codes for execution.

Difference Between Compiler and Interpreter

Syntax, Semantic and Runtime errors

• Vocabulary and rules define syntax.
• Syntax is the grammar of the language.
• Specifies allowed instruction structures.
• Semantics assigns meaning to words/symbols.
• Types of programming errors.

Syntax Error:

• Deviation from correct syntax leads to errors.
• Detected by the compiler during compilation.
• Program terminates, displays error messages.
• Examples: Misspelled names, missing semicolons, wrong brackets, incorrect statement formats.

Semantic Error:

• Related to program logic.
• Causes incorrect program operation.
• Program doesn’t terminate abnormally.
• Example: Incorrect formula like I = (P * T + R) / 100 for simple interest.
• Also called logical errors.

Runtime Error:

• Detected during program execution.
• Program compiles and runs but produces wrong results.
• Caused by data type mismatches.
• Challenging to identify and fix.
• Examples: Dividing by zero, accessing non-existent files.

Program Design tools

• Aid in planning software before coding.
• Include flowchart, pseudocode, UML, and interface tools.
• Enhance structure, logic, and user interface design.
• Contribute to efficient development and collaboration.

Algorithm:

• Step-by-step problem instructions.
• Written using programmer’s language.
• Not directly computer-tested.
• Vital documentation role.

Characteristic of algorithm are:

1. An algorithm must be simple and in easy language.
2. An algorithm should have finite number of steps.
3. The algorithm can be easily modified.
4. The algorithm should be able to produce accurate result.

Advantages

• Efficiency: Optimized solutions.
• Accuracy: Minimized errors.
• Reusability: Applicable to similar problems.
• Scalability: Works for varying input sizes.
• Logic Clarity: Step-by-step understanding.
• Problem Solving: Systematic approach for complexity.
• Communication: Facilitates sharing and collaboration.
• Savings: Reduces time and resource usage.

Disadvantages

• Complexity: Some algorithms can be intricate.
• Not Universal: Not all problems have efficient algorithms.
• Resource Intensive: High computing resources required.
• Expertise Needed: Designing advanced algorithms demands skill.
• Input Dependency: Performance varies with input.
• Inflexibility: Might not adapt to dynamic changes.
• Implementation Challenges: Converting algorithms to code can be complex.
• Lack of Creativity: Might not accommodate creative solutions.
• Learning Curve: Understanding complex algorithms can be demanding.

Flowchart:

• Graphical algorithm representation
• Uses various shapes for different instructions (input, logic, processing, output, etc.)
• Instructions written in boxes using English
• Vital for programming, aiding understanding of complex problems
• Helpful for visualizing logic in lengthy and intricate problems

Feature of Flowchart are:

1. Visual representation
2. Sequential steps
3. Decision points
4. Connectors and arrows
5. Symbolic notations
6. Easy-to-understand
7. Process visualization
8. Logic illustration
9. Hierarchical structure
10. Language-agnostic

Example:

Advantages:

1. It provides a clear overview of the entire problem.
2. It is easy to draw and understand.
3. It is independent of any programming languages.
4. It serves as a guide for program coding.

Disadvantages:

1. It is time consuming work.
2. It is difficult to translate flowchart into a program.
3. It is difficult to later time modification.
4. Some time it may be miscommunication.

Pseudocode

• ‘Pseudo’ means ‘fake’ or ‘false’
• Pseudo code is like a “fake” code for planning before actual coding
• It’s used after algorithm and flowchart creation
• Resembles program code but might not be syntactically correct
• Also referred to as ‘structured code’ or ‘structured English’
• Helpful in planning and organizing program logic before actual coding

Advantages:

• Clarity: Clear representation of program logic.
• Language-agnostic: Not tied to a specific programming language.
• Focus on Logic: Concentrates on problem-solving rather than syntax.
• Planning: Enhances program structure planning.
• Simplicity: Simplifies complex concepts.
• Collaboration: Facilitates teamwork and discussion.
• Time-Efficient: Reduces errors, saves coding time.
• Debugging: Easier error spotting and correction.
• Documentation: Serves as program design documentation.
• Learning: Useful for teaching programming concepts.
• Flexibility: Easily adaptable to changing requirements.

Disadvantages:

• Ambiguity: Can be imprecise, leading to different interpretations.
• Lack of Standards: No strict guidelines, causing confusion.
• Syntax Ignored: Syntax errors might be overlooked.
• Implementation Gap: Challenges translating into actual code.
• Limited Detail: Might not capture all complexities.
• Skill Required: Requires programming understanding.
• Simplicity Trap: Oversimplification of complex problems.
• Non-executable: Cannot be directly executed.
• Validation Lacking: No syntax validation or testing.
• Imagination Needed: Requires visualizing behavior for accuracy.

Control Structure: Sequence, Selection and Iteration

• Programs have standard structures.
• Programs consist of statements executed sequentially.
• Power increases with controlled statement execution.
• Execution can deviate from sequential order.
• Repetition and conditions need control structures.
• Control structures enable decision-making.
• Control structures can be categorized as

Sequence

• Executes statements sequentially.
• Order matters for successful execution.
• Previous step before next step.

Selection

• Based on condition, choose between paths.
• True outcome: one action; false outcome: another.
• Decision depends on a true or false condition.
• Known as Branching statement

Iteration

• Iteration is known as looping and involves repeated execution of instructions until a condition is satisfied.
• Loops have three components: initialization, condition, and counter.
• Initialization sets the loop’s starting point, condition determines when it stops, and the counter tracks iterations.
• Increment and decrement operators serve as counters.
• Infinite loops occur if the condition is always true.
• Three loop types: while, do while, and for loops.

Absolute binary, BCD, ASCIL, and Unicode (Code)

Absolute Binary:

• Representation of data using fixed binary values.
• Each bit directly represents a specific value.
• No encoding or special meanings associated.

BCD:

• Represents decimal digits (0-9) using 4 binary digits.
• Developed by IBM.
• Converts each digit to its binary equivalent.
• Allows coding of letters and special characters.
• Advantage: No size limit; easy to add digits.
• Contrast to binary format limits (8, 16, 32, 64 bits).
• Fast conversion from decimal to binary.
• Insufficient for business due to limited symbol representation (16, 24 symbols).

ASCII:

• Originally a seven-bit code, later expanded to eight bits.
• Developed for data transmission and processing.
• IBM introduced ASCII-8 with 256 symbols.
• Kept original 128 codes for compatibility.
• Common in data communication and micro-computers.
• Used for representing internal data.
• Table represents ASCII codes for symbols.

EBCDIC:

• Extended Binary Coded Decimal Interchange Code.
• Character encoding standard used mainly on IBM mainframes.
• Represents characters using 8-bit binary codes.
• Predecessor to ASCII and Unicode.

Unicode:

• Universal character encoding standard.
• Represents characters in text, web pages, etc.
• Supports all languages globally.
• ASCII supports 128 characters, Unicode supports 1,000,000+.
• Unicode uses up to 4 bytes per character.
• UTF-8 and UTF-16 common encodings.
• UTF-8 is efficient for English, others use more bytes.
• Used for diverse character representation.

C Programming Language

 Introduction and Feature of C Language

• Developed by Dennis Ritchie at Bell Labs (mid 1970s).
• Initially for systems programming, but versatile.
• Used in various applications from business to engineering.
• Popular for personal computers due to small memory requirements.
• First major use: UNIX operating system.
• Linked with UNIX historically, but now independent.
• Close to assembly language for efficiency.
• Enables writing efficient code.
• Can be challenging for certain application types.

Facts About C:

• Created for UNIX OS development.
• Successor of B language (early 1970s).
• Formalized by ANSI in 1988.
• Entire UNIX OS written in C.
• Widely used for System Programming.
• Many software and Linux OS use C.
• MySQL RDBMS developed in C.

Feature of C:

1. Easy learning due to the small command set.
2. Follows structured programming.
3. Provides machine independence.
4. Supports modular programming.
5. Acts as a bridge between high and low-level languages.
6. Faster execution than other languages.
7. Offers various data types and declarations.
8. Includes numerous built-in functions.
9. Powerful for commercial and hardware programming.
10. Programs independent of CPU used.

Advantage of C: 

1. Machine independent and portable.
2. Considered the foundation of modern languages.
3. Compiler widely accessible.
4. Combines high-level and low-level capabilities.
5. Known for fast execution.

Disadvantage of C:

1. Lacks runtime checking.
2. Challenging to fix errors in large programs.
3. Doesn’t support object-oriented programming.
4. Complexity may be difficult for beginners.

Structure of C program

• Several building blocks known as function.
• Function task independently.
• Basic structure of C program: Preprocessor and Header Files, void main function(), Comments, Compiling Process.

Preprocessor and Header Files

• Preprocessor:

• • • Pre-compilation phase.
    • Processes directives starting with ‘#’.
    • Handles tasks like macro substitution and conditional compilation.

• Header Files:

• • Contain declarations and sometimes definitions.
  • Modularize and organize code.
  • Included using ‘# include’ directive.
  • Commonly have ‘.h’ extensions.

Void main function ()

• Contain main () function.
• Written inside the scope {}.
• Actual program code are written in the executable part

Comments

• Comment are not internal part of program code.
• Writing comments helps to understand the flow of program.
• Practice for internal documentation of programmer.
• Use for further modification and program testing.

Compiling Process

• Process of converting source file into executable files.
• Automatically performed by the C compiler.

C Preprocessor and Header Files

• Header files, standard library file of C programming language.
• Detailed information about variables, constant, operators, etc.
• Files included program code before compilation.
• Preprocessor directives, include or link of header files to program codes
• List of header files are:
  • #include<stdio.h>
  • #include<conio.h>
  • #include<math.h>
  • #include<string.h >

Character Set used in C

• Define a group of letters, words, numbers, symbols, expressions used in C language.
• Some of them are:
  • Letters: uppercase A to Z and lowercase a to z.
  • Digits: 0 to 9
  • Special Characters: listed in the table.

Special Characters:

 Use of Comments

• Arbitrary text between /* and */.
• Enhance readability and understanding.
• Explain the program’s purpose.
• Not executable; ignored by compiler.
• Can be inserted almost anywhere except in constants.
• Aid in documentation, debugging, and testing.
• No impact on execution speed or program size.
• Helpful for programmers and users.
• Good practice for program clarity.
• Written in two form:
  1. //Single Line Comments
  2. /*Multi-Line………………………..comments*/

Identifiers, Keywords and Tokens

• Smallest part is called C tokens.
• Written by using these tokens 
• Types of C tokens are:

Keywords:

• Reserved by the C compiler
• Known as Keywords
• Identifiers in the program.

Identifiers:

• Name given to program units like: variables, structure, function, etc.
• Not define in programmer language
• But define by programmer
• Some rules are:
  1. Must start with an alphabet or underscore.
  2. Can consist of letters, digits, and underscore.
  3. Cannot be a standard C keyword.
  4. No spaces are allowed.
  5. Both uppercase and lowercase characters are valid.

Valid Identifiers

A1        B34        FIRST_NAME         x_1

Invalid Identifiers

1A        34AB        int       void        First-NAME        X.1

Basic Data Types in C

• Form of number, character, string or record are known as data types.
• Provide two data types: Primary data types and Secondary data types.

Primary Data Types:

• Known as fundamental data types
• Used to build other data types

Constants and Variables

Variables:

• Variables are named memory locations to store values of the same datatype.
• They are storage containers for values during program execution.
• Variables are declared before being used.
• Each variable must have a specified datatype.
• Data Type determines value range, type, and memory size.
• Rules of choosing variables name:
  1. 1. Can include uppercase and lowercase letters (A-Z, a-z).
     2. Can include digits (0-9) and underscore (_).
     3. Must start with a letter or underscore.
     4. Blank spaces are not allowed.
     5. Special characters like # and $ are not allowed.
     6. C keywords cannot be used as variable names.
     7. Variable names are case-sensitive.
     8. Values can be numeric or alphabetic.
     9. Variable types can be char, int, float, double, or void.
• Two main variable types:

Numeric Variable:

• • • Stored only numeric data
    • Maybe a whole number or a fractional number.
    • Example: integer, floating point, double

String Variable:

• • • Stored only character data 
    • May be single character or string
    • Example: table of string, character, array of character(string)

Constant:

• • Value don’t change during execution of program.
  • Has several types of constant.
  • Types of constant are:

1. Integer Constant

• • • Sequence of digits
    • Decimal integer, octal integer, hexadecimal are types
    • Example:

Decimal Integer          123       -31      0      +78

Octal Integer                 O26       O      O347     O676

Hexadecimal Integer OX2     OX8C        OXbcd        OX

2. Character Constant

• • • Stores only character
    • Enclosed by single quotation mark
    • Example:

                                   ‘A’          ‘B’          ‘h’          ‘2’          ‘6’

3. String Constant

• • • Set of character enclosed by double quotation mark
    • May be alphabet, number, special character and blank space.
    • Example:

                                    “VISHAL”          “1234”          “God Bless”          “!…?”

4. Symbolic Constant

• • • Substitute the value or expression to the constant name.
    • Using the pre-processor #define.
    • Example:

                                       #define PI 3.14

                                      #define name “HSEB”

                                     #define area 100

5. Escape Sequence Constant

• • Non-printing character starts with slash(\)
  • Special character used in output function
  • Table and meaning of escape sequence are:

Difference between Variable and  Constant 

Types of Specifier

• Known as format specifier.
• Types and format of value to be print or entered.
• Begins with % and ends with conversion character.
• Datatypes of the corresponding argument.

 Simple and Compound Statements

• Terminated by semicolon.
• Cause the computer to carry out some action.

Simple Statement:

• An expression followed by a semicolon.
• Causes the expression to be evaluated.

Compound Statement:

• Several individual statements enclosed in a pair of braces { }.
• Capability for embedding statements within other statements

Operators and Expressions

• Symbols carry out specific calculations or logical comparison.
• Variable or constant that holds data operation.
• Combination of operators and operands.
• Wide variety of operators

Arithmetic Operators:

• Perform simple arithmetic calculations like:  additions, subtraction, multiplication, etc
• Uses two operands so that it is called binary operator
• Types of arithmetic operators are:

Relational Operators:

• Compare two expressions.
• Bring out the decision accordingly
• Known as Comparison operator

Logical Operators:

• Used to give logical value i.e. true or false
• Compare or evaluate logical and relational expressions

Assignment Operators:

• Assign the value of expression into a variable.
• Written form: variable = expression

Unary Operators:

• Increment and Decrement operators are useful.
• Extensively used in loops
• Syntax of Operators are:
  • ++variable name (increment prefix)
  • variable name ++ (increment prefix)
  • – -variable name (decrement prefix)
  • variable name – – (decrement prefix)

Ternary Operator (? : operator):

• Known as conditional operator 
• Check the conditional to make a decision.
• Uses two symbol : (?) and (:)

The Comma Operator:

• Used to link related expressions together.
• Evaluated left to right and expression value of right

Expressions:

• Expressions combine variables, constants, and operators.
• Each expression evaluates to a value with a specific data type.
• Operators perform operations on operands within expressions.
• Type promotion and conversion ensure compatibility.
• Order of evaluation and side effects are important considerations.
• Expressions can be assigned to variables using the assignment operator.
• Parentheses control the order of evaluation.
• Function calls can be considered expressions if they return values.

Type Casting and Conversions

Implicit Type Conversion:

• Mixing of constants and variable of different types in expression
• Automatically converts any intermediate values to proper types.
• Evaluates without losing any significance

Explicit Type Conversion:

• Forcing type conversion differently from automatic.
• Called explicit conversion or casting.
• Used to change data types deliberately.

Introduction to Library Functions

• Function that pre-defined in programming language
• Used for input/output operations
• Function can perform specific tasks and return specific values.

 Input/output (I/O) Functions

• Provided by C compiler or C library.
• Collectively called Standard I/O Library functions.
• Used for input and output operations.
• Embedded in the stdio.h header file.
• Two main categories: Input and Output functions.

Other Input/Output Functions

• ‘getchar()’: Reads a single character.
• ‘putchar()’: Displays a character.
• Operate on individual characters.
• Used for character input/output

Selection Control Statement: Decisions (if, if-else, if-else-if, nested and switch)

Introduction to Control Statement

• Program execution is typically sequential, line by line.
• Not suitable for all scenarios, like making decisions.
• Decision-making statements verify conditions.
• Determine whether a block of code is executed.
• Used to solve problems where choices are needed.

Branching Statement

• Selection is made based on condition.
• Option to go when the given condition is true or false
• Totally directed by the result obtained from checking condition.
• Using selective control structure are called conditional statement
• Types of control used for decision making
• Two Categories are: Conditional Branching statement, switch-case statement
• Program executive based on the condition checked
• Used in different forms are:
  • If statement
  • If else statement
  • If else if statement
  • Nested if else statement

If statement:

• Verifies a given condition.
• Executes a block of statements if the condition is true.
• Skips the block if the condition is false.

If else statement:

• Verifies a given condition.
• Executes one of two blocks based on condition.
• If the condition is true, execute the true block.
• If the condition is false, execute the false block.

If else if statement:

• Used when multiple conditions need to be evaluated.
• Handles more than two possible actions.
• Provides a sequence of condition checks.
• Each condition is followed by a corresponding action.
• Only the action corresponding to the first true condition is executed.

nested if else statement:

• If statement inside another if statement.
• Referred to as a “nested if.”
• Helps create hierarchical conditions.
• Increases complexity for more intricate logic.

Switch case Statement:

• Suitable for selecting one option from many.
• Solves problems with multiple options efficiently.
• Simpler alternative to nested if statements.
• Compares a given value with values associated with options.
• Execution starts from the matched option (case).

Iteration Control Statement: Looping (while, do while, for nested)

Looping

• Repeatedly executing a set of instructions.
• Controlled by a specific number or condition.
• Part of control statements in C.
• Iteration statements are also called loops.
• Loops enable repetition in C programming.
• Types of looping are:

while loop:

• Repeats a statement or block while a condition is true.
• Executes as long as the condition remains true.
• Also known as “Entry control” looping statement.
• Rules of while loop are: 
  • Use the keyword “while” in lowercase.
  • If the condition involves a variable, assign a value before using it.
  • Modify the variable value within the ‘while’ block as needed.
  • The condition can be a direct integer value, variable, or a condition.

do while loop:

• Repeats a statement or block while a condition is true.
• Executes at least once before checking the condition.
• Also known as “Exit control” looping statement.

Difference between while loop and do while loop

for loop:

• Pre-tested loop for a known number of iterations.
• Consists of three parts: initialization, condition, and update.
• Control variable is initialized first.
• Condition is tested, and the loop continues if true.
• If the condition is false, the loop terminates.
• Statements in the loop body are executed.
• Control variable is updated and the condition re-evaluated.
• Loop continues until the condition becomes false.

Nested Loop:

• Nested loop: loop within a loop.
• Outer loop triggers the inner loop.
• Inner loop executes completely.
• Outer loop triggers inner loop for each iteration.
• Process repeats until the outer loop finishes.

Infinite Loop:

• Repeats program statements endlessly.
• Lacks a termination condition.

Jumping Statement

• Used to control program flow.
• Execute or skip program statements.
• Three types: break, continue, and goto.

break Statement:

• Terminates ‘switch’ case statements.
• Terminates looping statements: ‘while’, ‘do-while’, and ‘for’.

continue Statement:

• Used inside loops.
• Jumps to the loop’s beginning for the next iteration.
• Skips the execution of statements within the loop for the current iteration.

goto Statement:

• Used to jump between lines in a program.
• Enables jumping top-to-bottom or bottom-to-top.
• Requires a label as the target destination.
• Label is a name for an instruction or line.
• Execution control jumps directly to the labelled line.

Array: definition, types (1D and 2D), matrix addition and subtraction

Introduction to Array

• Used for managing large numbers of similar data values.
• Provides a single variable to store multiple values of the same type.
• Offers easier handling and organization of data.
• Stores values in continuous memory locations.
• Enhances efficiency in accessing and managing data.

Characteristics of Array:

• Collection of elements of the same data type.
• Elements stored in contiguous memory locations.
• Accessed using an index or position.
• Fixed size determined during declaration.
• Elements can be accessed and manipulated efficiently.
• Can be used to represent lists, tables, matrices, etc.

Advantages of Array:

1. Random Access: Elements can be accessed directly using array indices.
2. Code Efficiency: Requires fewer lines of code for multiple elements.
3. Simplified Access: Provides easy access to all elements.
4. Efficient Traversal: Can be traversed easily using a single loop.
5. Simplified Sorting: Sorting is easier with fewer lines of code.

Disadvantage of Array:

1. Fixed Size: Array size is determined during declaration and cannot be changed.
2. Limited Dynamic Behavior: Unlike linked lists, arrays are not dynamic in nature.
3. Costly Insertion and Deletion: Inserting and deleting elements can be inefficient due to memory reallocation and shifting.
4. Memory Management: Array elements need to be managed explicitly with new memory allocation.
5. Static Structure: Array structure is static, making it less flexible for changing data requirements.

Types of Arrays

• Arrays are classified into two types.
  • Single Dimensional Array / One Dimensional Array
  • Multi Dimensional Array

One Dimensional Array:

• Used to store a list of values of the same data type.
• Store data in a linear, sequential form.
• Often referred to as one-dimensional arrays or linear arrays.
• Suitable for representing a row of values.

Array Initialization

• Arrays can be initialized during declaration using curly braces {}.
• Use commas to separate the initialization values within the curly braces.
• Partial initialization is allowed; remaining elements will be set to zero.
• For complete initialization, the array’s dimension is not needed; the compiler will adjust it based on the provided data.

Multi Dimensional Array:

• Multi-dimensional arrays consist of arrays within arrays.
• They have more than one dimension or size.
• Examples include two-dimensional, three-dimensional, and higher-dimensional arrays.
• Two-dimensional arrays are commonly used to store tabular data and matrices.

String: Definition and String Function: strlen(), strcat(), strcamp(), strrev(), strcpy(), strlwr(), strupr()

Introduction to string

• Strings are sets of characters enclosed in double quotes.
• Strings are created using one-dimensional arrays of the character data type.
• Strings are terminated with a NULL character (‘\0’).
• The C compiler automatically appends a NULL character at the end of a string.
• Strings in C are represented as character arrays of a single dimension.

String Handling Functions

• Pre-defined functions for working with string values.
• Defined in the string.h header file.
• Need to include string.h before using these functions.
• Example:
  • strrev() function
  • strcpy() function
  • strcat() function
  • strcmp() function

Array of Strings:

• Array of strings is a dimensional array of characters.
• Also called a table of strings.
• Useful for sorting string-related problems.
• Can be treated like a two-dimensional array.

Introduction of Office Package

Microsoft Office

• Suite of desktop productivity apps.
• Designed for office/business use.
• Proprietary product by Microsoft.
• Released in 1990.
• Available in multiple languages.
• Supported by Windows, Mac, Linux.
• Includes Word, Excel, PowerPoint, Access, OneNote, Outlook, Publisher.

Concept of Word Processor

• Software for composing, editing, formatting, printing documents.
• Used in business, home, education.
• Creates, edits, prints, and saves documents.
• Examples: Microsoft Word, WordPerfect, AppleWorks, OpenOffice.org.

Feature of Word Processing:

1. Document creation.
2. Writing, editing, saving, and opening documents.
3. Formatting options (font, size, color, style, etc.).
4. Background, foreground, and word art features.
5. Spelling checker and thesaurus for proofreading.
6. On-screen reading and revision.
7. Insertion of graphics, audio, and video.
8. Ability to produce multiple copies of documents.

Applications of Word Processing:

1. Document creation (letters, reports, memos)
2. Academic work (research papers, assignments)
3. Business communication (emails, contracts)
4. Publishing (newsletters, brochures)
5. Data analysis (tables, charts)
6. Collaboration (track changes, comments)
7. Legal documents (agreements, correspondence)
8. Content for blogs/websites
9. Creative writing (poems, stories)
10. Personal use (resumes, letters)

Types of Word Processing

1. MS Word
2. Word Perfect
3. Word Star
4. Lotus Notes

Presentation Tools

Concept of Presentation

• Creates slideshows
• Combines text, images, audio, and video
• Supports storytelling and information presentation
• Used for business and academic purposes
• Examples: Microsoft PowerPoint, Apple Keynote, OpenOffice Impress, Corel Presentations, Adobe Persuasion, Flowboard, Kingsoft Presentation, Prezi

Feature of Presentation Software:

1. Detailed topic overview
2. Audio-video integration on slides
3. Simple to interactive presentation
4. Built-in design and animation tools
5. 2D and 3D text editing
6. Conversion to movie file

Application of Presentation Software:

1. Creating slideshows for lectures and presentations.
2. Business proposals and reports.
3. Pitching ideas to investors.
4. Educational content for classrooms.
5. Marketing and sales presentations.
6. Conference and seminar materials.
7. Showcasing data visually.
8. Interactive multimedia presentations.
9. Collaborative team projects.
10. Remote and online presentations.

Example Of Presentation Program:

1. Microsoft PowerPoint
2. Apple Keynote
3. OpenOffice Impress
4. Prezi, Google Slides
5. Canva, Haiku Deck.

Types of Presentation

1. Static Presentation:

• Runs automatically from start to end without user interaction. 
• Used for continuous subject description.

2. Interactive Presentation:

• Requires user interaction (keyboard, mouse, etc.) to move between slides. 
• Commonly used in education and official presentations.

Spreadsheet Package

• Spreadsheet organizes data into rows and columns.
• Used for analysis and calculations.
• Examples: Microsoft Excel, Google Sheets, OpenOffice Calc.

Fundamental of SpreadSheet

1. Grid of rows and columns.
2. Cells store data, text, or formulas.
3. Formulas perform calculations.
4. Functions are predefined operations.
5. Charts visualize data.
6. Sorting and filtering organize data.
7. Data analysis and modeling.
8. Collaboration and sharing features.
9. Common formats like Excel, Google Sheets.

Some Feature of SpreadSheet:

1. Handles large data volumes.
2. Provides built-in functions.
3. Offers accurate results.
4. Supports decision making.
5. Includes word processing features.
6. Offers database capabilities.
7. Graphs, charts, and pivot tables for data representation.
8. Integration with other software programs.

Application of SpreadSheet:

1. Financial analysis and modeling.
2. Budgeting and expense tracking.
3. Data organization and management.
4. Inventory management.
5. Project planning and tracking.
6. Statistical analysis and calculations.
7. Business forecasting.
8. Sales and revenue tracking.
9. Employee scheduling.
10. Data visualization and charts.

Database Management System

Introduction

• Software for creating, managing, and organizing databases.
• Ensures data integrity, security, and concurrency control.
• Abstracts technical complexities of data management.
• Vital tool for businesses to manage data efficiently.
• Important Terms of database:
  1. Data
  2. Information
  3. Field
  4. Record
  5. Table
  6. Database

Database Management System (DBMS)

• Software for storing and retrieving user data.
• Consider security measures.
• Manages data manipulation and retrieval.
• Accepts data requests from applications.
• Instructs the OS to provide specific data.
• Aids users and third-party software in data storage and retrieval.
• Allows users to create custom databases.
• Interfaces between data and software applications.

Advantage of DBMS:

1. Controls database redundancy.
2. Restricts unauthorized access.
3. Offers storage structure and query processing techniques.
4. Provides backup and recovery.
5. Supports multiple user interfaces.
6. Enforces data constraints.
7. Reduces application development time.

Disadvantage of DBMS:

1. Complex, time-consuming database design.
2. High hardware and software startup costs.
3. Database damage affects many applications.
4. Significant conversion costs from file-based to database systems.
5. Initial training required for programmers and users.
6. Regular backup requirements leading to additional storage costs.

Introduction to Domain-specific Tools

• Specialized software for specific industries or tasks.
• Tailored to meet distinct requirements of a domain.
• Offer precise features, workflows, and data handling.
• Enhance efficiency, accuracy, and collaboration.

Domain Specific Tools Advantages

• Purpose-built:

• • • Precise solutions for specific tasks.
    • Optimized workflows for efficiency.
    • Specialized features and functionalities.
    • Improved data integrity and security.
    • Enhanced collaboration within the domain.
    • Tailored interfaces for user ease.
    • Compliance with industry standards.
    • Targeted problem-solving.
    • Increased productivity.
    • Streamlined processes.

• Self_contained:

• • • Focused functionality for specific tasks.
    • Reduced complexity without unnecessary features.
    • User-friendly interfaces for domain experts.
    • Streamlined workflows for efficiency.
    • Data integrity specific to the domain.
    • Enhanced security measures.
    • Less training required due to specialization.
    • Improved accuracy in domain-related tasks.
    • Facilitates quick decision-making.
    • Minimized risk of errors.

School Management System

• Manages school activities and processes.
• Facilitates campus management.
• Handles examinations, attendance, admissions, fees, timetable, teacher training, and more.
• Tracks school vehicles.
• Promotes interaction among teachers, students, and parents.

Feature of School Management System Project:

1. Student management (enrollment, attendance, grades).
2. Teacher management (schedules, assignments).
3. Parent and guardian portals (access to info, communication).
4. Administrative tools (staff, inventory, finances).
5. Timetable creation and management.
6. Communication tools (messaging, announcements).
7. Library and resource tracking.
8. Transportation management (routes, assignments).
9. Exam and assessment management.
10. Reports and analytics.
11. Security and access control.
12. Online admission and enrollment.

Inventory Management

• Manages purchase, sales, orders, delivery, and stock maintenance.
• Ensures stocks are maintained above specified limits.
• Helps with timely purchase and deliveries.
• Aids in forecasting and utilizing economies of scale.
• Useful for efficient timing of inventory activities.

Purpose of Inventory Management System Project:

1. Efficiently track and manage inventory levels.
2. Streamline stock ordering and restocking processes.
3. Minimized overstocking or stockouts.
4. Optimize resource allocation and utilization.
5. Improve accuracy in inventory records.
6. Facilitate timely reorder notifications.
7. Enhance demand forecasting and planning.
8. Reduce manual data entry and errors.
9. Enable real-time visibility into inventory.
10. Support effective cost management.
11. Streamline vendor and supplier relationships.
12. Enhance decision-making through data insights.
13. Provide better control over inventory-related costs.

Feature of Inventory Management System Project:

1. Product tracking and lifecycle management.
2. Inventory control with reorder points.
3. Barcode scanning for quick identification.
4. Real-time updates and visibility.
5. Reporting and analytics for data-driven decisions.
6. Supplier management and relationships.
7. Multi-location support for varied sites.
8. User access control with permissions.
9. Integration with other systems.
10. Mobile app compatibility for on-the-go access.

Payroll Management System

• Handles employee salary, leaves, bonuses, loans.
• Efficiently manages employee information.
• Generates pay-slips with a click.
• Ensures data security.
• Often part of HR software in large organizations.

Feature of payroll management system:

1. Salary calculation and processing.
2. Leave management.
3. Bonus and incentive management.
4. Tax calculation and deduction.
5. Loan and advance tracking.
6. Attendance and overtime tracking.
7. Employee self-service portal.
8. Direct deposit and payment methods.
9. Tax compliance and reporting.

Financial Accounting

• Tracks all organizational financial transactions.
• Maintains electronic records.
• Manages financial data systematically.

Objectives of financial accounting:

1. Records transactions for analysis and statements.
2. Calculates profit/loss for strategy adjustments.
3. Assesses a company’s financial health (assets, liabilities).
4. Share information with stakeholders for decisions.

Feature of financial accounting:

1. Profit and loss calculation.
2. Balance sheet preparation.
3. Cash flow statement analysis.
4. Audit trail and data accuracy.
5. Tax calculation and compliance.
6. Integration with other systems.
7. Reporting and analytics capabilities.
8. Data security and access controls.
9. Financial statement generation.

Hotel Management System

• Manages hotel operations (front office, sales, planning, accounting).
• Tracks inventory, orders, customer data.
• Aids employee scheduling and management.
• Facilitates table booking and reservations.

Feature of Hotel Management Software:

1. Reservation and booking management.
2. Front desk operations.
3. Guest check-in and check-out.
4. Room allocation and availability tracking.
5. Billing and invoicing.
6. Housekeeping and maintenance scheduling.
7. Restaurant and banquet management.
8. Point of Sale (POS) integration.
9. Online booking and payment processing.
10. Guest communication and feedback.

Weather Forecasting System

• Real-time software predicts weather.
• Uses live data (temperature, humidity, wind).
• Forecasts natural disasters (earthquakes, hurricanes).

Objective of Study:

1. Predicting future atmospheric conditions.
2. Providing timely and accurate weather information.
3. Assisting public safety and disaster preparedness.
4. Supporting agriculture, transportation, and industries.
5. Enabling informed decision-making for various sectors.
6. Enhancing understanding of climate patterns.
7. Mitigating risks and minimizing impacts of severe weather.

Feature of weather forecasting software:

1. Real-time data collection (temperature, humidity, wind).
2. Meteorological model integration.
3. Multi-day forecasts.
4. Visualization and maps.
5. Severe weather alerts.
6. Historical data analysis.
7. Regional and global coverage.
8. User-friendly interfaces.

 Concept of Software

 Definition of Software:

• Organized computer data & instructions.
• Function: Control, integrate, manage hardware; perform tasks.
• Role: Instruct computer, manage control sequences.
• Interaction: Software gives instructions, hardware executes.
• Nature: Intangible, user cannot physically touch.

Relationship Between Software and Hardware:

• Software: Computer programs loaded into the system.
• Hardware: Visible devices forming computers.
• Importance: Blend of software and hardware vital.
• Function: Software controls hardware, like a driver to a car.
• Relationship: Hardware (‘heart’) and software (‘soul’) complement.
• Vital Pair: Both essential, working together.

Categories of Software:

• Software: Set of programs for defined tasks.
• Sequence of instructions, problem-solving.
• Some categories of software are: System software, Application software 

System Software:

• System software: Bridges user and hardware interaction.
• Function: Manages hardware, offers essential user functions.
• Intermediary: Between user and hardware, like the middle layer.
• Platform: Provides an environment for other software.
• Importance: Crucial for computer system management.
• Initialization: Loads into memory at computer startup.
• Background: Operates behind scenes, not for end-users.
• Term: Also called ‘low-level software’.
• common system software examples are:

1. Operating System

• • • Operating system: Essential for computer operation.
    • Role: Controls computer activities, user-hardware link.
    • Function: Enables user-hardware cooperation.
    • Support: Needed for running software (word processing, etc.).
    • Examples: MS DOS, Windows, UNIX, LINUX, Mac OS, Android.

Operating System (OS) Functions:

1. 1. Hardware management
   2. Process scheduling
   3. Memory allocation
   4. File system organization
   5. User interfaces
   6. Security control
   7. Device communication
   8. Error handling
   9. Networking support
   10. Software execution environment
   11. System services
   12. Virtualization (in some cases)

 2. Utility Software

• • • Enhance computer functionality.
    • Categories: antivirus, backup, disk repair, file management, security, networking.
    • Include screensavers, font tools, desktop enhancements.
    • Maintain system health and performance.
    • Aid customization and user interface.

Example of Utility Software are:

Antivirus:

• Guards against viruses, malware.
• Detects, notifies, takes action.
• Examples: Norton, Kaspersky, McAfee.

Disk Management:

• Manages drives, partitions.
• Examples: Paragon Partition Manager, MiniTool Partition Wizard.

Compression:

• Reduces file sizes.
• Examples: WinZip, WinRAR, WinAce.

Disk Cleanup:

• Deletes unnecessary files.
• Increases storage, system speed.
• Examples: CCleaner, Advanced SystemCare.

Backup:

• Creates file, database copies.
• Recovers lost data.
• Examples: Norton Ghost, TotalRecovery Pro.

File Management:

• Manages computer files.
• Tasks: search, update, browse.
• Examples: Directory Opus, Windows File Manager.

3. Language Processor

• Translate programs written in one to another.
• Mediate high-level to machine-level code.
• Translate code for software execution.
• Example: 
  • • • Compiler
      • Interpreter
      • Assembler

Application Software:

• User-focused, task-specific.
• Essential for computer use.
• Single programs (Notepad) or packages (spreadsheets).
• Controlled by system software.

Used for a variety of purposes:

• As a business tool.
• Assist with graphics, multimedia projects.
• Support home, personal, education.
• Facilitate communication support.
• Aid in the entertainment industry aid.

Types of Application Software

1. Package Software:

• Task-specific software.
• User-friendly, readymade.
• Used for various purposes by many users.
• Types packaged software:

Word Processing Software

• Computer-based document tasks.
• Word processing software enables creation, editing, formatting, storage, retrieval, printing.
• Examples: WordStar, WordPerfect, MS Word, WordPad.

Database Software

• Creates, maintains, organizes databases.
• Enables data retrieval.
• Examples: dBase, FoxPro, MS Access, Oracle, SQL.

Spreadsheet Software

• Analyzes numeric data.
• Creates computerized ledgers.
• Examples: Lotus 1-2-3, Excel.

Multimedia Software

• Combines text, graphics, audio, video.
• Used for editing video, audio, text.
• Applications: business, education, entertainment.
• Examples: VLC, Windows Media Player, VLMC, Media Conversion Tools, Multimedia Editing Tools, Video Editing Tools.

Presentation Software

• Displays information as slides.
• Includes text, graphics, video, images.
• Components: Text editor, multimedia insertion, slideshow.
• Simplifies idea presentation.
• Examples: PowerPoint, Keynote.

Web Based Software

• Hosted on web servers, accessed via browsers.
• Data stored online, accessible from any device.
• No need for local software installation.
• Utilized through a web browser.
• Easy integration into websites.
• Cloud applications with no local storage/RAM requirement.
• Examples: Google Classroom, voice recognition, etc.

Mobile Apps

• Developed for smartphones, tablets.
• Provide various services.
• Small software units with specific functions.
• Utility, productivity, entertainment, etc.
• Popular in social media, various fields.
• Enhanced interactivity and mobile-friendly format.

2. Tailored Software:

• Custom-made for specific needs.
• Designed for individuals or organizations.
• Examples: NEB result processing, Tally Accounting, Medi-Pro, Billing software, School information system, etc.

Concept of Operating System

Introduction of Operating System

• Bridge between hardware, software.
• Essential for computer operation.
• Computer’s “heart” – controls operations.
• Manages input, output, files, peripherals.
• Interface between hardware and User
• Send instruction to the hardware
• Example: Linux, Mac OS, Microsoft Windows, and UNIX, etc. 

1. OS Kernel

• • Core of operating system.
  • Manages hardware resources.
  • Provides essential services.
  • Controls processes, memory, devices.

2. Utility Software

• • Enhances computer functionality.
  • Examples: antivirus, backup, disk cleanup, compression.
  • Supports tasks like data management, system maintenance.

3. OS Application

• •  Software that runs on an operating system.
  • User-focused, performs specific tasks.
  • Example: Paints, WordPad, Notepad, Games, etc.

Role of Operating  System

1. Memory Management:

• Tracks memory status (allocated/free).
• Allocates memory among processes.
• Manages programs in memory.

2. Peripheral Management:

• Device driver handles peripherals.
• Translates requests, data, and messages.
• Controls device activity.

3. Hardware Interface Management:

• Manages wires, plugs, sockets.
• Enables hardware communication.

4. Storage Allocation:

• Reads, stores, writes data on disk.
• Assigns ownership, permissions.
• Manages data storage location.

5. Time-Slicing (Swapping):

• Allots processing time per user or program.
• Enables multitasking illusion.

 Functions of Operating System:

• Interface between user and hardware.
• Manages computer system resources.

1. Input Output (I/O) Management

• Manages input-output in computer system.
• Device managers handle devices.
• Coordinates device assignments to programs.
• Recognizes keyboard, mouse input.
• Sends output to display, printer.
• Controls peripheral devices.

2. Command Interpreter

• Reads user-typed commands via terminal.
• Interprets and translates for hardware.
• OS-specific, varies across systems.
• Essential for OS operation.

3. Data Management

• Organizes data into files.
• Arranges data in logical groups.
• Sorts data (e.g., numerical, alphabetical).

4.Files management

• Tracks file information.
• Creates folders, sub-folders, files.
• Moves, organizes files in directory hierarchy.
• Manages folders, sub-folders, files.
• Enables efficient file searching.

5. Memory Management

• Array of words/bytes, each with address.
• OS allocates memory to processes.
• Free memory when the process ends.
• Enables efficient memory utilization.

6. Job Management

• Controls execution of multiple jobs or tasks.
• Schedules and allocates resources for tasks.
• Manages job queue, prioritization.
• Ensures efficient CPU utilization and job completion.

7. Process Management

• Manages running processes.
• Handles multitasking, CPU sharing.
• Allocates CPU time to processes.
• Determines execution order.
• FCFS principle (or priority-based in some cases).
• Ensures efficient CPU utilization

8. User Interface

• Provides interaction between user and system.
• Offers graphical or command-line interfaces.
• Enables users to issue commands, navigate, perform tasks.
• Ensures ease of use and efficient interaction.

9. Interrupt-handling

• Signal from device/program to computer.
• Halts normal processing.
• Requires CPU attention.
• Enhances system efficiency.
• External devices request CPU focus.

10. Security Management

• Crucial due to system, data, network concerns.
• OS responsibility: computer, data, user, programmer security.
• Controls system access.
• Manages user accounts, passwords.
• Offers encryption for data protection.

11. Deadlock Prevention

• Deadlock: resource conflict halting processes.
• OS prevents deadlock by resource allocation.
• Allocates resources cautiously.
• Ensures processes continue smoothly.
• Averts resource conflicts.

12. Time Sharing

• Allocates CPU to multiple processes.
• Manages CPU time distribution.
• Creates illusion of sole user.
• Each user/process gets time slice.
• Utilizes CPU speed advantage.
• Supports multi-user interaction.

13. Virtual Storage Management

• Used for programs larger than RAM.
• Utilizes secondary memory (e.g., hard disk).
• Program divided into pages.
• Only needed pages stay in main memory.
• Rest stored in secondary memory.
• Loaded when needed.
• Virtual storage: area in secondary memory for pages.
• Technique are:

• Paging:

• • Divides memory and programs into fixed-size pages.
  • Pages are stored in main memory or secondary storage.
  • Allows flexible allocation of memory.
  • Efficient memory usage.
  • Simplifies memory management.
  • Supports larger programs.

• Swapping:

• • Moves the entire process in/out of main memory.
  • Temporary relocation to secondary storage.
  • Frees up space for other processes.
  • Helps manage limited memory efficiently.
  • Ensures optimal resource utilization.
  • Avoids unnecessary program termination.

Operating System Terminology

• Multitasking Operating System:

• • Executes multiple tasks concurrently.
  • Allows simultaneous use of different programs.
  • Enables efficient task switching.
  • Examples: Editing and browsing simultaneously.
  • Enhances user productivity.
  • Supports concurrent program execution.

• Multiprocessing Operating System:

• • Multiple CPUs in a single computer system.
  • CPUs closely connected, share data.
  • Communication between processors.
  • Shared resources: memory, buses, devices.
  • Used for high processing speed.
  • Scientific calculations, data analysis.
  • Applications like weather forecasting.
  • Efficient for data-intensive tasks.

Windows Operating System

 Introduction to GUI based Operating System and Its Features

• Popular since the 1990s (Windows, macOS).
• Integral graphical interface.
• Ease-of-use environment over command line.
• Non-experts access and use computers.
• GUI: Graphical User Interface.
• Uses mouse, images for interaction.
• Windows, Icons, Menus, Pointing devices (WIMPs).
• WYSIWYG: What You See Is What You Get.
• Eliminates need to remember keywords.
• Menus replace commands.
• Relates desktop environment to physical workspace.

GUI Advantages and Disadvantages:

Advantages:

1. Beginner-friendly.
2. Cut, paste, drag-and-drop info exchange.
3. User-friendly interaction.

Disadvantages:

1. High memory, processing needs.
2. Slower than the command line.
3. Can be complex for simple tasks.
4. Main GUI components: Windows, Icons, Menus, Pointer (WIMP).
5. Examples: Windows 10, macOS, Ubuntu.

Features of GUI:

1. Visual interaction with images, icons.
2. Mouse-based navigation.
3. Windows: Separate on-screen areas for apps.
4. Icons: Represent files, programs.
5. Menus: Dropdown lists for commands.
6. Pointing devices (e.g., mouse, touchpad).
7. WYSIWYG: Accurate on-screen to print output.
8. User-friendly, intuitive interface.
9. Used in Windows, macOS, Linux distributions.

Open Source and Mobile Operating System

Concept of Open Sources Operating

• Accessible, modifiable source code.
• Users can fix, enhance, improve code.
• Open source operating systems:
  • • • • GNU/Linux (Debian, Fedora, Ubuntu, etc.)
        • OpenSolaris
        • FreeBSD
        • Android (mobile phone platform)

Advantages:

• Customization: Modify to fit specific needs.
• Flexibility: Adapt to changing requirements.
• Cost-effective: No licensing fees.
• Community Support: Collaboration for improvement.
• Security: Faster bug fixes, updates.
• Transparency: Code review, assurance.
• Innovation: Encourages creativity, diverse solutions.
• No Vendor Lock-in: Not tied to single provider.
• Reliability: Many eyes on code, quick issue resolution.

Disadvantages:

• Lack of Support: Limited or paid support options.
• Complexity: Learning curve for new users.
• Compatibility: Interoperability challenges with proprietary software.
• Fragmentation: Various distributions, versions.
• Security Risks: Vulnerabilities due to open code.
• Lack of Polished UI: Some may lack user-friendly interface.
• Limited Hardware Support: Not all devices/drivers may be supported.
• Potential Forks: Development divergence can lead to multiple versions.
• Legal and Licensing Issues: Compliance concerns for commercial use.

Free Software

• Refers to software with freedom for users.
• Freedom to use, modify, distribute.
• Not necessarily cost-free.
• Upholds user rights.
• Example: GNU General Public License (GPL).
• Promotes collaboration, sharing.

Introduction to UNIX, Linux

UNIX:

• Portable, multitasking, multiuser, time-sharing OS.
• Originated in 1969 by AT&T employees.
• Initially in assembly language, reprogrammed in C (1973).
• Identified with open systems concept.
• Ported to various machine families.
• Common in PCs, servers, mobile devices.
• Essential for Internet, networking development.
• Varieties of UNIX are: Sun Solaries, GNU/Linux and MacOS X.

The UNIX Operating System

The Kernel:

• Connects hardware and user.
• Central software component.
• Manages files, memory, devices, processes, network.
• Ensures system and user tasks correctness.
• Essential for smooth OS operation.

The Shell:

• Intermediary between user and kernel.
• Translate typed commands.
• Shell scripts are sequences of commands.
• Two major types: Bourne shell, C shell.
• Bourne shell: default in Version 7 Unix.

The program:

• Wide range of built-in programs.
• Text editors (vi, nano), compilers (gcc), utilities (ls, cp).
• Shell programs (bash, sh) for command-line interaction.
• Networking tools (ssh, ftp) for communication.
• System administration tools (useradd, chmod).
• Programming libraries and tools (libc, make).
• Offers diverse functionality for users and administrators.

Linux

• Freely distributable, Unix-based.
• Cross-platform, installed on various devices.
• PCs, laptops, mobiles, tablets, servers, more.
• Packaged as Linux distributions.
• Includes Linux kernel, tools, libraries.
• Common distributions: Debian, Ubuntu, Fedora, Red Hat, openSUSE.

Advantage of Linux:

• Open Source: Freedom to modify, distribute.
• Stability: Reliable, fewer crashes.
• Security: Less vulnerable to malware.
• Customization: Tailor to specific needs.
• Performance: Efficient resource usage.
• Cost-effective: No licensing fees.
• Community Support: Collaboration, solutions.
• Compatibility: Works on various hardware.
• Versatility: Runs on diverse devices.

Disadvantage of Linux:

• Learning Curve: May require new skills.
• Software Compatibility: Some apps not available.
• Hardware Compatibility: Limited drivers.
• Gaming: Fewer gaming options.
• User Interface: UI inconsistencies.
• Support: Limited official support for some distributions.
• Enterprise Adoption: Less common in some industries.
• Commercial Software: Less commercial software available.
• Fragmentation: Numerous distributions, versions.

Some LINUX commands

• mkdir – Its used to make directories

Syntax: mkdir directory

Example: mkdir ram

• cd – cd command is used to changed directories

Syntax: cd directory

Example: cd hello

• mv – To changed the name of directory mv command is used.

Syntax: my old_directory_namenew_directory_name

Example: mv testdir newnamedir

• rmdir – It remove an existing directory.

Syntax: rmdir directory

Example: rmdir directory

• cp – To copy files from one place to another cp command in used.

Syntax: cp source destination

Example: cp myfiles yourfile

• cal month year – It prints a calendar for the specified month of the specified year.

Example: cal 12 1987

• cat files – It prints the contents of the specified files.

Syntax: cat files_name

Example: cat newyear

• clear – It is used to clear the terminal screen.

Syntax: clear

• cmp files 1 files 2 – It compares two files, reporting all discrepancies. Similar to the diff command, though the output format differs.
• free – free command displays the amount of used and free system memory.

Linux Distributions

• OS based on Linux kernel.
• Includes software collection, package management.
• Users download distributions.
• Available for various systems (embedded to supercomputers).
• Examples: OpenWrt (embedded), Linux Mint (PCs), Rocks Cluster (supercomputers).
• some popular Linux operating system are:

1. Ubuntu

• Created by Canonical in 2004.
• Focus on user-friendly graphical interface.
• Derivative of Debian.
• Popular, well-known Linux distribution.
• Designed for ease of use, minimal command line.
• Comes with pre-installed apps, repositories.
• Transitioned from GNOME2 to Unity desktop.
• Frequent releases every six months.
• Expanding to tablets, smartphones.

2. Fedora

• Focuses on free software, latest versions.
• Doesn’t create its own desktop environment.
• Relies on “upstream” software.
• Default desktop environment: GNOME3.
• Emphasizes latest features over stability.

3. Linux Mint

• Based on Ubuntu, shares repositories.
• Originated as Ubuntu alternative.
• Includes media codecs, proprietary software.
• Gained popularity over time.
• Uses Cinnamon, MATE desktop environments.
• Distinct from Ubuntu’s Unity desktop.

Concept of Mobile Operating System

• Platform for mobile devices (PDAs, smartphones, etc.).
• Evolved from PC-based to smartphone-oriented.
• Driven by hardware, software, Internet advancements.
• Popular OSs: Android, Symbian, iOS, BlackBerry, Windows Mobile.
• Defines device features, functions (keypads, sync, email, etc.).
• Manages wireless connections, multimedia, input methods.
• Similar to standard OS, but simpler and lighter.

 Types of Mobile Operating System

1. Android OS (Google Inc.)

• Developed by Open Handset Alliance, led by Google.
• Unveiled in November 2007.
• Core under open source Apache License.
• Proprietary software includes Play Store, Google services.

Feature of Android:

• Open Source: Customizable, accessible code.
• User Interface: Flexible, rich UI options.
• App Ecosystem: Vast selection on Play Store.
• Multitasking: Switch between apps smoothly.
• Notifications: Interactive, informative alerts.
• Customization: Widgets, themes, launchers.
• Connectivity: Seamless integration with Google services.
• Hardware Compatibility: Supports various devices.
• Security: Regular updates, app permissions.
• Cloud Integration: Syncing, backup, storage.

2. iPhone OS/IOS (Apple)

• Developed by Apple Inc.
• Exclusive to Apple hardware.
• Powers iPhone, iPad, iPod Touch, Apple TV.
• Closed source, proprietary.
• Built on open source Darwin core OS.
• Introduced direct manipulation for user interaction.
• Focused on small screens, limited input devices.

Feature of iPhone OS/iOS (Apple):

• Sleek User Interface: Clean, intuitive design.
• App Store: Curated apps, high-quality standards.
• Optimized Performance: Smooth operation on Apple hardware.
• Security: Regular updates, stringent app review.
• Privacy: User data protection, app permission control.
• iCloud Integration: Seamless data syncing, backup.
• Seamless Ecosystem: Integration with Apple devices.
• Siri: Voice assistant for tasks, queries.
• Face ID/Touch ID: Secure biometric authentication.
• ARKit: Augmented reality development platform.

3. Windows Mobile (Windows Phone)

• Developed by Microsoft for smartphones, Pocket PCs.
• Integrates Xbox Live, Xbox Music, video experience.
• Extends Windows desktop to portable devices.
• Three types: Standard, Professional, Classic.
• Seamlessly integrates with Microsoft services.
• Offers familiar Windows interface on mobile devices.
• Supports various types of mobile hardware.
• Used on PPC mobile phones, PDAs, portable music players.

Feature of Windows Mobile:

• Familiar Interface: Windows-like user experience.
• Microsoft Integration: Seamless access to Microsoft services.
• Multitasking: Run multiple apps simultaneously.
• Office Integration: Microsoft Office apps.
• Cortana: Voice-powered virtual assistant.
• Live Tiles: Dynamic, informative home screen icons.
• Customization: Personalize start screen, apps layout.
• Security: Device encryption, app sandboxing.
• Universal Apps: Apps across Windows devices.
• Xbox Integration: Xbox Live games and services.

4. BlackBerry OS (Research in Motion)

• Developed by Research In Motion (RIM).
• Designed for BlackBerry handheld devices.
• Offers synchronization with business software.
• Particularly beneficial for corporate users.
• Supports Microsoft Exchange, GroupWise, Lotus Domino.
• Known for security and enterprise features.
• Historically popular among business professionals.

Feature of BlackBerry OS:

• Security: Strong encryption, data protection.
• Push Email: Instant email delivery.
• BlackBerry Messenger (BBM): Secure messaging.
• Enterprise Integration: Synchronization with business software.
• BlackBerry Hub: Unified communication hub.
• Physical Keyboard: Many devices feature physical QWERTY keyboards.
• Efficient Messaging: Priority Hub, filters.
• Remote Device Management: Admin controls for business use.
• BlackBerry Balance: Separates work and personal data.
• BlackBerry World: App store for BlackBerry apps.

5. Symbian OS (Nokia)

• Mobile operating system with communication integration.
• Based on the Java language.
• Combines wireless communications and PIM.
• Developed by Symbian Ltd in 1998.
• Originally designed for mobile phones.
• First used by Nokia in its mobile devices.

Feature of Symbian OS (Nokia):

• User-Friendly Interface: Easy navigation and operation.
• Multitasking: Running multiple apps simultaneously.
• Customization: Themes, layouts, and profiles.
• Messaging: SMS, MMS, email, and IM support.
• Integrated PIM: Contacts, calendar, tasks, notes.
• Java Support: Allows running Java apps.
• Connectivity: Bluetooth, Wi-Fi, USB.
• Media Playback: Music, video, image viewing.
• Web Browsing: Basic web browsing capabilities.
• Extensibility: Support for third-party apps.

What is Number System?

• Mathematical notation for representing numbers consistently.
• Uses symbols/digits to express quantities and values.
• Used in math, computing, engineering, etc.

Types of Number System:

1. Non-positional Number System

• • Early counting used fingers, stones, or sticks.
  • Additive approach or non-positional system.
  • Symbols like I, II, III used for values.
  • Symbols added for total value.
  • Hard for arithmetic; led to positional systems.
  • Example: Roman Numeric

2. Positional Number System

• • Positional systems use digits with varying values.
  • Digit’s value is based on itself, position, and base.
  • Different systems based on base value:
    • • • Decimal
        • Binary
        • Octal
        • Hexadecimal

Radix of a Number System:

• Radix of a number: Also called its base.
• Represents the number of unique symbols in a number system.
• Determines counting and positional structure.
• Decimal system (base-10) has a radix of 10 (0 to 9).
• Binary system (base-2) has a radix of 2 (0 and 1).
• Hexadecimal system (base-16) has a radix of 16 (0-9 and A-F).
• Radix influences mathematical operations and representation rules.

Why Binary number system is used in computer system?

• Digital Nature: Computers operate using electronic components that have two stable states: “on” and “off,” corresponding to binary digits 1 and 0.
• Simplicity: Binary representation aligns with the basic operation of electronic switches, like transistors, which can have two states.
• Reliability: Binary states are distinct, making it easier to differentiate between them and accurately detect changes.
• Efficiency: Binary arithmetic involves straightforward operations (addition, subtraction), which can be efficiently implemented using digital circuits.
• Memory Cells: Computer memory cells store individual bits, aligning well with binary representation (0 or 1).
• Compatibility: Binary representation allows seamless communication between computer components, such as processors, memory, and input/output devices.
• Logical Operations: Binary logic gates (AND, OR, NOT) are essential for designing computer components and executing instructions.
• Error Handling: Binary representation simplifies error detection and correction mechanisms, ensuring data integrity.
• Encoding: Communication protocols use binary encoding for transmitting and storing data accurately.
• Uniformity: Binary representation provides a standardized way to handle various tasks and data types consistently in computer systems.

Decimal/Binary/Octal/Hexadecimal Number System & Conversion

Decimal Number System:

• Base-10 system.
• Digits 0-9.
• Positional: Each place represents power of 10.
• Common for human calculations.

Binary Number System:

• Binary system: 0 and 1.
• Base-2 system, simplest due to two digits.
• Binary digits called “Bits”.
• 4 Bits = nibble, 8 Bits = byte.
• Represents devices’ ON and OFF states.
• Base value of binary is 2 (subscripted as B).
• Example: (1010)2 or (1010)B.

Octal Number System:

• Octal system: 8 digits – 0 to 7.
• Base-8 system, simpler than binary.
• Easier handling compared to binary arrays.
• Octal array shorter than binary.
• Base value of octal is 8 (subscripted as O).
• Grouping bits for binary representation.
• Used in some assembly languages for instructions and addresses.
• Early computing systems with word sizes divisible by three.

Hexadecimal Number System:

• Hexadecimal: 10 digits (0-9) and 6 letters (A-F).
• A-F represent 10-15.
• Base-16 system, used in microprocessors.
• Different systems represent same quantities.
• Symbols change, quantities stay constant.
• Compact representation of binary data.
• Common for memory addresses, debugging, and low-level programming.
• Representing colors in graphics (HTML/CSS).
• Network addresses (IPv6) and file formats.

Number System Conversion

Decimal to Other System Conversion

Conversion from decimal to binary

Rules:

1. Divide the decimal number by the base value of binary (2) and list the remainder.
2. The process is continuing till the quotient becomes zero.
3. Write the remainders left to right from bottom to top.

Example:

Convert (34)10 into Binary.

Solution:

Given number: 34

Let’s convert it to binary:

∴ (34)10 = (100010)2

Fractional conversion (Decimal to Binary):

Rules:

1. Successively multiply the fraction by 2 (base 2) to generate binary digits.
2. Repeat until the fraction becomes 0 or until the desired accuracy is reached.
3. If the fraction becomes 0, terminate the process.
4. If the fraction does not become 0 after 5 iterations, terminate the process after the 5th iteration.

Example:

Convert (23.84)10 into Binary.

Solution:

Given number: 23.84

Let’s convert the non fractional part first:

∴ (23)10 = (10111)2

Now, let’s convert the fractional part:

∴ (.84)10 = (.11010)2

Finally,

(23)10 + (.84)10 = (10111)2 + (.11010)2 

∴ (23.84)10 = (10111.11010)2

Converting Decimal to Octal

Rules:

1. Divide the decimal number by the base value of Octal (8) and list the remainder.
2. The process is continuing till the quotient becomes zero.
3. Write the remainders left to right from bottom to top.

Example: 

Convert the decimal number 109 into octal.

Solution:

Given number: 109

Let’s convert it to octal:

∴ (109)10 = (155)8

Fractional conversion (Decimal to Octal):

Rules:

1. Successively multiply the fraction by 8 (base 8) to generate binary digits.
2. Repeat until the fraction becomes 0 or until the desired accuracy is reached.
3. If the fraction becomes 0, terminate the process.
4. If the fraction does not become 0 after 5 iterations, terminate the process after the 5th iteration.

Example:

Convert (23.84)10 into Octal.

Solution:

Given number: 23.84

Let’s convert the non fractional part first:

∴ (23)10 = (27)8

Now, let’s convert the fractional part:

∴ (.84)10 = (.65605)8

Finally,

(23)10 + (.84)10 = (27)8 + (.65605)8 

∴ (23.84)10 = (27.65605)8

Converting Decimal to Hexadecimal

Rules:

1. Divide the decimal number by 16 and list the remainder.
2. The process is continuing till the quotient becomes zero.
3. Write the remainders left to right from bottom to top.

Example: 

1. Convert the decimal number 53 into Hexadecimal number.

Solution:

Given number: 53

Let’s convert it to octal:

∴ (53)10 = (35)16

Example: 

1. Convert decimal number 235 into Hexadecimal number.

Solution:

Given number: 235

Let’s convert it to Hexadecimal:

Here, since it is hexadecimal values, we know:

14 = E

11 = B

∴ (235)10 = (EB)16

Fractional conversion (Decimal to Hexadecimal):

Rules:

1. Successively multiply the fraction by 16 (base 16) to generate binary digits.
2. Repeat until the fraction becomes 0 or until the desired accuracy is reached.
3. If the fraction becomes 0, terminate the process.
4. If the fraction does not become 0 after 5 iterations, terminate the process after the 5th iteration.

Example:

Solution:

Given number: 31.84

Let’s convert the non fractional part first:

Here, since it is hexadecimal values, we know:

15 = F

∴ (31)10 = (1F)16

Now, let’s convert the fractional part:

Here, since it is hexadecimal values, we know:

13 = D

10 = A

∴ (.84)10 = (.D70A3)16

Finally,

(31)10 + (.84)10 = (1F)16 + (.D70A3)16 

∴ (31.84)10 = (1F.D70A3)16

Other System to Decimal Conversion

Converting From Binary to Decimal

Rules:

1. Multiply each binary digit with its place value i.e. positive powers of two with its positional weight.
2. Add all the products.

Example: Convert Binary number 111111 into decimal no.

Given number: 11111

Let’s first find out positional weight for each binary digit:

Now, let’s convert: 

 = (1 × 25 + 1 × 24 + 1 × 23 + 1 × 22 + 1 × 21 + 1 × 20)

 = 32+16+8+4+2+1

 = 63

∴ (111111)2 = (63)10

Fractional conversion (Binary to Decimal):

Example:  Convert Binary number 110011.11into decimal no.

Given number: 110011.11

Let’s first find out positional weight for each binary digit:

Now, let’s convert: 

 = (1 × 25 + 1 × 24 + 1 × 23 + 1 × 22 + 1 × 21 + 1 × 20  + 1 × 2-1 + 1 × 2-2)

 = 32+16+0+0+2+1+0.5+0.25

 = 51.75

∴ (110011.11)2 = (51.75)10

Conversion from Octal to Decimal

Method:

1. Multiply each octal digit with its place value (8) with its positional weight.
2. Add all the products.

Example: Convert octal number 435 into Decimal number.

Given number: 435

Let’s first find out positional weight for each octal digit:

Now, let’s convert: 

= (4 × 82 + 3 × 81 + 5 × 80)

= (4 × 64 + 3 × 8 + 5 × 1)

= (256+24+5)

= 285

∴ (435)8 = (285)10

Fractional conversion (Octal to Decimal):

Solved examples of octal fractions to decimal fraction conversion

Example: Convert (21.21)8 into base 10

Given number: 21.21

Let’s first find out positional weight for each octal digit:

Now, let’s convert: 

= 2 × 81 + 1 × 80 + 2 × 8-1 + 1 x 8-2

= 2 × 8 + 1 × 1 + 2 × ( 1 / 8 ) + 1 × ( 1 / 64 )

= 16 + 1 + ( 0. 25 ) + ( 0.015625 )

= 17 + 0. 265625

 = 17.265625

∴ (21.21)8 = (17.265625)10

Conversion from Hexadecimal to Decimal

Method:

1. Multiply each hexadecimal digit with its place value(16) with its positional weight.
2. Add all the products.

Example: Convert hexadecimal number AB2 into decimal.

Given number: AB2 

Let’s first find out positional weight for each hexadecimal digit:

Here, since it is hexadecimal values, we know:

A = 10

B = 11

Now, let’s convert: 

(10 × 162 + 11 × 161 + 2 × 160 )

= (10 × 256 + 11 × 16 + 2 × 1)

= (2560 + 176 + 2) =2738

∴ (AB2)16 = (2738)10

Fractional conversion (Hexadecimal to Decimal):

Example: Convert ( E F . B 1 )16= ( ? )10

= E × 161 + F × 160 . B × 16-1 + 1 x 16-2

= 14 × 16 + 15 × 1 . 11 × ( 1 / 16 ) + 1 × ( 1 / 256 )

= 224 + 15 . ( 0. 6 8 7 5 ) + ( 0 . 0 0 3 9 0 6 2 5 )

= 239 + 0. 6914

= 239 . 691406

Therefore ( E F . B 1 )16 = ( 2 3 9 . 6 9 1 4 0 6 )10

Binary to Octal and Hexadecimal Conversion

Conversion from Binary to Octal

Method 1:

1. Write the Binary number in group of 3 from right hand side.
2. If any digits are inadequate for such group of 3, then add zeros before the number.
3. Write its corresponding value of octal from the table or convert it to decimal as before.

Example: Convert Binary number 10110 into Octal.

Binary number: 10110

Grouped Binary Number: 010     110

Corresponding Octal Value: 2      6 [Taken from the table]

Or

Given number: 10110

Let’s first find out positional weight for each binary digit:

Now, let’s convert: 

 = ( 0 × 22 + 1 × 21 + 0 × 20)

 = 0+2+0

 = 2

Similarly,

 = ( 1 × 22 + 1 × 21 + 0 × 20)

 = 4+2+0

 = 6

Concatenating above results. We get:

∴ (10110 )2 = (26)8

Method -2:

1. First convert the Binary number into Decimal number.
2. Now convert the decimal number into Octal number.

Example: Convert Binary number 10110 into Octal.

Given number: 10110

Let’s first find out positional weight for each binary digit:

Now, let’s convert to decimal first: 

= (1 × 2 4 + 0 × 23 + 1 × 22 + 1 × 21 + 0 × 20)

= 16 + 0 + 4 + 2 + 0

= 22

Therefore, (10110)2 = (22)10

Again, let’s convert decimal to octal:

Therefore (22)10 = (26)8

∴ (10110)2  = (26)8

Fractional conversion (Binary to Octal):

Example: Convert (0110 011.1011)2 into base 8

Binary number = (0110 011.1011)2

Group of 3 bit of Binary = (0 110 011 . 101 1)2

= (110 011 . 101 100)2

Now, let’s convert: 

 = ( 1 × 22 + 1 × 21 + 0 × 20)

 = 4+2+0

 = 6

Similarly,

 = ( 0 × 22 + 1 × 21 + 1 × 20)

 = 0+2+1

 = 3

Similarly,

 = ( 1 × 22 + 0 × 21 + 1 × 20)

 = 4+0+1

 = 5

Similarly,

 = ( 1 × 22 + 0 × 21 + 0 × 20)

 = 4+0+0

 = 4

Concatenting above results. We get:

Thus, (0110 011.1011)2 = (63.54)8

∴ (0110 011.1011)2  = (63.54)8

Conversion from Binary to Hexadecimal

Method -1:

1. Write the binary number in a group of 4 from right to left. 
2. If any digits are inadequate for such a group 4, then add 0 before the number as much is necessary. 
3. Write the equivalent Hexadecimal number from the table or convert binary to decimal as before.

Example: Convert Binary number 10110 into Hexadecimal.

Binary Number: 10110

Grouped Binary Number: 0001     0110

Equivalent Hexadecimal number:   1     6 [taken from the table]

Or

Now, let’s convert: 

 = ( 0 x 23  + 0 × 22 + 0 × 21 + 1 × 20)

 = 0+0+0+1

 = 1

Similarly,

 = ( 0 x 23  + 1 × 22 + 1 × 21 + 0 × 20)

 = 0+4+2+0

 = 6

Therefore, (10110) 2 = (16)16

Method -2:

1. Convert the given binary number into Decimal number 
2. Now convert decimal number into Hexadecimal number.

Example: Convert Binary number 10110 into Hexadecimal.

Let’s first find out positional weight for each binary digit:

Now, let’s convert to decimal first: 

= (1 × 2 4 + 0 × 23 + 1 × 22 + 1 × 21 + 0 × 20)

= 16 + 0 + 4 + 2 + 0

= 22

Therefore, (10110)2 = (22)10

Again, let’s convert decimal to octal:

Therefore (22)10 = (16)16

∴ (10110)2  = (16)16

Fractional conversion (Binary to Hexadecimal):

Method -1:

1. Write the binary number in a group of 4 from right to left. 
2. If any digits are inadequate for such a group 4, then add 0 before the number as much is necessary. 
3. Write the equivalent Hexadecimal number from the table or convert binary to decimal as before.

Example: Convert (11110.01011)2 into Base 16

Binary Number: 11110.01011

Grouped Binary Number: 0001   1110   0101   1000