Internet Basics | Computer Application: Class 10 PDF Download

History of Internet

ARPANET Development:

• In 1969, the University of California at Los Angeles and the University of Utah established the ARPANET.
• ARPANET was initiated and sponsored by the U.S. Department of Defense (DoD).
• The purpose was to connect computers at various universities and defense organizations.
• Initial connections were made using 56 kbit/s circuits.

NSFnet Creation:

• In the mid-1980s, the National Science Foundation (NSF) introduced NSFnet.
• NSFnet offered higher capacity and capabilities compared to ARPANET.
• However, it limited its use to academic research and excluded private businesses.

Rise of Private Networks:

• Due to NSFnet's academic focus, private organizations and individuals began creating their own networks.
• These networks, known as private networks, emerged to serve diverse purposes.
• In the 1990s, efforts were made to connect private networks with ARPANET and NSFnet.

Formation of the Internet:

• The integration of ARPANET, NSFnet, and private networks culminated in the creation of the Internet.
• The Internet gained widespread popularity in the 1990s, particularly with the development of the World Wide Web (WWW).

Working of Internet

Internet Connectivity:

• Computers on the Internet are interconnected through small networks.
• These networks connect to the Internet backbone through gateways.

TCP/IP Protocol:

• All Internet-connected computers communicate using TCP/IP (Transmission Control Protocol/Internet Protocol).
• TCP/IP is a fundamental set of rules governing Internet communication.

Packet Transmission:

• TCP/IP manages data transmission by dividing files/messages into smaller packets or datagrams.
• Each packet consists of data and an address section, with addresses for both the source and destination, up to 1500 characters.

TCP Functionality:

• TCP (Transmission Control Protocol) breaks messages into smaller packets for Internet transmission.
• It also reassembles received packets back into the original message.

IP Functionality:

• IP (Internet Protocol) handles the addressing aspect of each packet to ensure data reaches the correct destination.
• Gateways on the network examine these addresses to determine where to forward the message.

Uses of Internet

• The Internet is a pivotal modern technology benefiting daily, personal, and professional aspects of our lives.

Internet Uses:

• E-Commerce: Includes online auctions and buying/selling products.
• Research: Access to online journals, magazines, and information.
• Education: Facilitates e-learning and distance learning.
• E-Governance: Enables online application submissions, income tax, sales tax, etc.
• E-Reservation: Supports online booking and ticket reservations.
• Online Payments: Allows for credit and debit card payments.
• Video Conferencing: Enables virtual meetings.
• Exchange of Views: Sharing files, music, folders, etc.
• Social Networking Sites: Platforms like Facebook and Twitter.
• Entertainment: Access to music, videos, games, etc.

Advantages of Internet:

• Access to information reduces research time.
• Facilitates easy communication with others.
• Provides global connectivity.
• Saves paper through online document publishing.
• Offers a valuable platform for advertising and business.

Disadvantages of Internet:

• Potential for cyber fraud involving credit/debit card information.
• Inappropriate and harmful content accessible to malicious individuals.
• Source of computer viruses.
• Messages can be intercepted and abused.
• Difficulty in verifying the accuracy of online information.

Internet Governance:

• The Internet is not controlled by a single organization.
• Volunteer groups assist in its development and coordination.
• Key organizations include:
  • Internet Architecture Board (IAB): Provides oversight of Internet architecture.
  • Internet Engineering Task Force (IETF): Develops and maintains communication protocols.
  • Internet Research Task Force (IRTF): Addresses long-term research issues.
  • Internet Network Information Center (InterNIC): Offers registry services.
  • World Wide Web Consortium (W3C): Develops web standards.
  • Internet Society (ISOC): Focuses on Internet growth and utilization.

Connecting to the Internet

Dial-up Connection:

• Temporary connection between computer and ISP server.
• Uses telephone line (Public Switched Telephone Network - PSTN) and modem.
• Modem dials ISP's phone number.
• Connection takes about 10 seconds with beeping sounds.

Broadband Connection:

• High-speed, always-on Internet access.
• Measured in Mbps (Megabits per second).
• Types of broadband technologies:
  • Digital Subscriber Line (DSL): Uses local telephone network.
  • Cable Modem: Uses co-axial cables for TV.
  • Broadband over Power Line (BPL): Uses electric power distribution network.
• Backbone of the Internet connects networks.
• ISP provides Internet connections.
• Modem stands for Modulator and Demodulator.
• Bandwidth is data capacity.
• TCP/IP is the standard for Internet communication.

Popular ISPs in India:

• Data Communication Ltd.
• Mahanagar Telephone Nigam Ltd. (MTNL)
• Airtel
• Reliance

Wireless Connection:

• Connects using radio link.
• Can be mobile or fixed.
• No modem or cables needed.
• Distance doesn't affect data transfer rate.

Wireless Internet Technologies:

• Wireless Fidelity (Wi-Fi): Uses radio frequencies, private or public access.
• Worldwide Interoperability for Microwave Access (WiMAX): High-speed, long-range wireless technology.
• Mobile Wireless Broadband Services: Suitable for mobile users, lower speeds.

Some advantages and disadvantages of different connection types are as follows:

Satellites which are orbiting around the earth, provide necessary links for telephone and television service. They can also provide links for broadband. Satellite broadband is another form of wireless broadband and is also useful for serving remote or sparsely populated areas.

World Wide Web (WWW)

• A system of Internet servers supporting hypertext and multimedia.
• Often abbreviated as the Web.
• Facilitates access to various Internet protocols through a single interface.
• Part of the Internet and its fastest-growing component.
• Enables individuals, organizations, and companies to publish information.
• Useful for finding information on various topics.

Protocol:

• A set of rules coordinating information exchange.
• Sender and receiver must follow the same protocol for communication.

Web Protocols:

• HTTP (HyperText Transfer Protocol): Transmits hypertext over networks, stateless protocol of the Web.
• SMTP (Simple Mail Transfer Protocol): Distributes email messages and attachments.
• FTP (File Transfer Protocol): Transfers files between servers and computers.
• VoIP (Voice over Internet Protocol): Delivers voice communications over IP networks.
• POP (Post Office Protocol): Primary protocol for email communication.
• IMAP (Internet Message Access Protocol): Standard for accessing email from local servers.

WWW Attributes:

• User-friendly: Compatible with most web browsers.
• Multimedia documents: Supports graphics, audio, video, animation, and text.
• Interactive: Provides interactivity with hyperlinks and input boxes.
• Frames: Allows multiple independent sections on a single web page.

HyperText and Hyperlinks:

• Hypertext: Text with clickable links to other linked pages.
• Hyperlink: An icon, graphic, or text linking to another document.

Web Page

• Composed of files or documents known as pages or Web pages.
• These pages contain information and links to various resources, including text and multimedia.
• Created using HTML (HyperText Markup Language).
• Web pages are interconnected through hyperlinks.

Nature of the Web:

• A vast collection of computer documents or Web pages.
• These pages are stored on computers worldwide.
• Connected to each other using hyperlinks.

Website

• A website is a collection of related web pages connected by hyperlinks, sharing a common theme, and existing under the same domain.
• Each website is accessible through a unique address called a URL (Uniform Resource Locator).

Home Page:

• The primary or initial page of a website is referred to as the home page.
• Advantages of a Home Page:
  • Helps visitors understand the site's content.
  • Promotes individuals or communities.
  • Creates a welcoming experience for visitors.

Web Portal:

• A web page that integrates valuable information and links is known as a web portal.

Advantages of a Web Portal:

• Allows users to personalize their online experience.
• Facilitates communication between different applications.
• Offers flexibility in content and layout.

Web Browser

• A software application used to locate, retrieve, and display content on the World Wide Web.
• Serves as an interface for users to access internet content.
• Multiple web browsers can be installed on a single computer.
• Allows users to navigate files, folders, and websites.
• Two types of web browsers:
  • Text Web Browser: Displays text-based information (e.g., Lynx).
  • Graphical Web Browser: Supports both text and graphic information (e.g., Internet Explorer, Firefox, Safari, Chrome, Opera).
• Popular graphical web browsers:
  • Netscape: Introduced in 1994.
  • Internet Explorer (IE): Introduced in 1995 by Microsoft.
  • Safari: Developed by Apple, included in Mac OS X, supports modern technologies.
  • Firefox: Derived from Mozilla, released in 2004, the second most popular browser.
  • Google Chrome: Developed by Google, released in 2008 for Windows.
  • Opera: Compact, fast, fully-featured, popular mobile web browser.
• World Wide Web (WWW) introduced on March 13, 1989.
• NCSA Mosaic was the first graphical web browser.
• Web portal: A website with hyperlinks to many other websites.
• Intranet: Private computer networks within an organization, also called a corporate portal or private business network.

Web Server

• A computer program that serves requested HTML pages or files to Web clients.
• Web clients, such as Web browsers, request HTML files from Web servers.
• Each Web server connected to the Internet has a unique IP address, consisting of four numbers (0 to 255) separated by periods (e.g., 68.178.157.132 or 68.122.35.127).
• Web server software typically requires a robust operating system like Unix or Windows NT.
• Websites are stored on Web servers for access.

Five major Web servers commonly used for hosting websites:

Apache HTTP Server:

• Developed by Apache Software Foundation.
• The most popular Web hosting server globally.
• Compatible with various operating systems, including Windows, Linux, Mac OS X, and UNIX.
• Currently used on 60% of server machines.

Internet Information Server (IIS):

• A Microsoft product known for high performance.
• Easily manageable and integrated with Windows platforms.

Lighttpd:

• A free Web hosting server distributed under the BSD license.
• Considered fast, reliable, and power-efficient.
• Compatible with Windows, Linux, Mac OS X, Unix, and Solaris.

Sun Java System Web Server:

• Developed by Sun Microsystems.
• Supports Windows, Linux, and Unix operating systems.
• Also supports various technologies, scripts, and languages, including PHP, PERL, ASP, Coldfusion, and Python.

Jigsaw Server:

• A free open-source server for website hosting from W3C.
• Written in Java and supports PHP programs and CGI scripts.
• Compatible with multiple platforms like Linux, Mac OS X, Windows, Unix, and FreeBSD.

Web Address and URL

• The web is a vast collection of documents or web pages stored on computers worldwide.
• Each web page has a unique address known as a web address or domain name.
• Web addresses are commonly referred to as URLs (Uniform Resource Locators).
• URLs pinpoint the exact location of a specific web page or resource on the internet.

Parts of a URL:

• URLs consist of three main components: a. Protocol: Specifies the method used to access the file resource, such as "http://" or "https://." b. Domain Name: Identifies a specific computer or server on the internet. c. Path Name: Provides a hierarchical description of the file's location within that computer.

Types of URLs:

• URLs come in two primary types: a. Absolute URL:
  • Specifies the precise location of a file or directory on the internet.
  • Each absolute URL is unique; identical URLs point to the same file.
  • Format: scheme://server/path/resource, where "scheme" is the protocol used. b. Relative URL:
  • Points to a file or directory in relation to the current file or directory.
  • Uses an absolute URL as a starting point.
  • Typically includes the path and optionally the resource, but no scheme or server.

Domain Name

• A domain name is essentially a textual label that corresponds to a computer's numeric IP address on the Internet.
• It serves as a means for Internet users to access a specific website; for instance, by typing in the domain name.
• The purpose of a domain name is to identify and locate computers connected to the Internet.
• Each domain name must be unique to ensure accurate identification and location of different Internet resources.
• A standard feature of domain names is their structure, which includes two or more parts separated by periods (dots), such as in "google.com" or "yahoo.com".

Domain Abbreviation

Domain are organised by the type of organisation and by the country. A three letter abbreviation indicating the organisation and usually two letter abbreviation indicating the country name. Most common domain abbreviations for organisation are as follows:

Some domain abbreviations for country are as follows:

Domain Name System (DNS)

• DNS (Domain Name System) functions to translate domain names, which are the host names of computers, into their corresponding IP addresses.
• Beyond simple translation, DNS is responsible for storing and linking various types of information with domain names.
• It offers a global service that allows keyword-based redirection across the internet.
• DNS is designed for rapid updates, highlighting its efficiency and dynamic nature.
• The system also defines the technical specifications for the database service it operates on.
• The structure used to identify servers within the DNS is referred to as the domain name system.
• An example of DNS at work is the translation of a domain name like "www.example.com" into an IP address such as "198.105.232.4".

Numeric Computer IP Address

IP Addresses

• Format: IP addresses are in the format aaa.aaa.aaa.aaa, where each 'aaa' is a number ranging from 0 to 255.
• Length: The total length of an IP address is 4 bytes.
• Purpose: IP addresses uniquely identify host computers to ensure information packets reach the correct destination. For example, an IP address like 162.192.1.89.
• Characteristics:
  • Uniqueness: Each IP address is unique.
  • Exclusivity: No two machines have the same IP address.
  • Global Standardization: IP addresses are global and standardized, with all internet-connected machines using the same scheme.
  • Functionality: They specify the source or destination of network communications.

E-mail Address

• Definition: E-mail, short for ‘Electronic Mail,’ is a method of sending messages, notes, pictures, and sound files electronically.
• Usage: It is used for sending and receiving messages over the Internet.
• Format: An E-mail address is in the format user@domain, where:
  • "user" is a unique username.
  • "@" symbol separates the user from the domain.
  • "domain" identifies the mail server.
• Examples: Popular E-mail service providers include Gmail, Yahoo! Mail, Rediffmail, etc.

Blogs

• Definition: A blog is a website or web page for recording opinions and linking to other sites, updated regularly.
• Content: Typically combines text, images, and links to other blogs and web pages.
• Use in Education: Known as edublogs when used for instructional purposes.
• Author: A person who writes a blog is called a blogger.
• Activity: Blogging is the act of posting content on a blog.

Advantages:

• Flexible working hours.
• Requires minimal effort to write.
• Easy and quick updates.
• Allows for audience engagement through comments.
• Potential for increased revenue.
• Quick setup.
• Encourages social interaction and response to queries.

Disadvantages:

• Potential isolation.
• Unstable income.
• Health issues can affect blog updates and income.
• Loss of traffic and income if not regularly updated.

Newsgroup

• Definition: An online discussion group for a specific topic, part of a computer network or the Internet.
• Operation: Functions through an electronic bulletin board system (Usenet) and chat sessions.
• Classification: Divided into categories like rec, news, sci, soc, comp.
• Storage: Uses Network News Transfer Protocol (NNTP) servers.
• Moderation: Can be moderated or unmoderated.
• Examples: alt.tennis, alt.astrology, comp.lang.C++.

Advantages:

• Structured similarly to mailing lists but better organized.
• Easier to access.
• Frequently includes helpful FAQs.
• Free subscription and posting.

Disadvantages:

• Slower than email or mailing lists.
• Risk of misinformation.
• Not very user-friendly and higher virus risk.

Hypertext Transfer Protocol (HTTP)

• Function: Protocol for data transfer over the World Wide Web.
• Process: Defines message formatting and transmission, and the responses of web servers and browsers.
• Example: Entering a URL triggers an HTTP command to the web server to fetch the requested web page.
• Relation to HTML: Works alongside HTML, which formats and displays web pages.
• Nature: Stateless protocol, executing each command independently.