Internet Basics and History

Internet Basics

• Internet is a global system of interconnected computer networks.
• Uses 'interconnection' and 'networks' to describe the system.
• Networks are collections of two or more computers that share information and resources.
• Internet enables computers worldwide to exchange information.
• Internet is used for e-mail, web browsing, and finding information.

History of Internet

• In 1969, the ARPANET (Advanced Research Projects Agency Network) was created by the University of California at Los Angeles and the University of Utah.
• Connected by 56 kbit/s circuits, sponsored by the U.S. Department of Defense (DoD).
• Goal was to connect computers at different universities and U.S. defense locations.

Working of Internet

• Computers on the Internet are interconnected through smaller networks.
• These networks are linked through gateways to the Internet backbone.
• Computers communicate using TCP/IP (Transmission Control Protocol/Internet Protocol).
• IP handles addresses, TCP breaks data into packets (small pieces), then reassembles them at the destination.

Uses of Internet

• E-commerce (buying and selling)
• Research (journals, magazines)
• Education (online learning)
• E-governance (online forms)
• E-reservation (online bookings)
• Online payments (credit/debit cards)
• Video conferencing
• Social networking
• Entertainment (music, videos, games)

Advantages of Internet

• Faster access to information
• Easier communication with others globally
• Easier advertising and business processes

Disadvantages of Internet

• Cyber frauds (credit card use)
• Unwanted material (child abuse content)
• Spread of viruses
• Accuracy of information isn't always confirmed
• Privacy concerns (messages passing through various computers without security)

Who Governs the Internet?

• The internet is not governed by a single organization.
• There are volunteer groups that coordinate its development.
• Some examples include the Internet Architecture Board (IAB), Internet Engineering Task Force (IETF), Internet Research Task Force (IRT) and Internet Network Information Center (InterNIC).

Connecting to the Internet

• Dial-up Connection: A temporary connection using telephone lines and modems.
• Broadband Connection: High-speed, always-on connection using telephone lines, cable TV lines or power lines (BPL).
• Digital Subscriber Line (DSL): Uses existing copper telephone lines.
• Cable Modem: Uses cable TV lines.
• Broadband over Power Line (BPL): Uses electricity lines as a connection path.
• Wireless Connections: Uses radio waves to connect to the internet

Wireless fidelity (Wi-Fi)

• A universal wireless networking technology using radio frequencies.
• Designed for private and public access in houses, businesses, and public spaces.

Worldwide Interoperability for Microwave Access (WiMAX)

• A broadband wireless technology.
• Provides broadband wireless access at higher speeds and over greater distances than Wi-Fi.

Internet Protocols

• Protocols are rules that govern computer communication over networks
• HTTP (hypertext transfer protocol): the basic protocol used for transferring information across the web via web pages.
• TCP/IP (Transmission Control Protocol/Internet Protocol): A set of rules that computers use to communicate with each other over the internet.
• FTP (File Transfer Protocol): Used to transfer files over the internet.
• Secure Copy Protocol (SCP)
• Secure Shell (SSH): A secure remote login protocol used to create connection from one computer to another.
• SMTP (Simple Mail Transfer Protocol): A protocol used to send and receive emails.
• POP3 (Post Office Protocol Version 3): A protocol used to retrieve emails from a mail server to a local email client.

Internet Services

• Web Pages: Basic unit of web information and can be accessed using a web browser.
• Websites: Made of related web pages.
• Web Browsers: Software applications used to access websites and webpages. E.g., Firefox, Safari, Chrome, opera.
• Hyperlinks: Links to other web pages.
• Hypertext Markup Language (HTML): The markup language used to create web pages.
• URL (Uniform Resource Locator): The address of a web page.
• Domain names: Text-based name that correspond to specific IP addresses.
• Blogs: Online journals used for posting information, opinions or links.

Network Systems

• Internet: Worldwide network of networks.
• Intranet: Company network.

Domain Name System

• Converts human-readable domain names into computer-understandable numerical IP addresses.

World Wide Web (WWW)

• System of Internet servers that supports multimedia and hypertext to access information.

E-mail

• Electronic messages sent via the internet