The Internet and the World Wide Web

Introduction to the Internet and the World Wide Web

• Definition of the Internet: The Internet, often referred to simply as the ‘Net,’ is a ‘network of networks.’ It is the largest computer network in the world, connecting billions of computer users globally.
• Etymology: The word ‘internet’ is derived from a combination of the words ‘interconnection’ and ‘Network.’
• Definition of a Network: A network is a collection of computers and devices connected through communication channels and transmission media. This infrastructure allows for the sharing of various resources, including:
  • Hardware
  • Software
  • Data
  • Information
• Ownership: Generally, no single entity or person owns the internet.

Brief History and Evolution of the Internet

• ARPA (Advanced Research Project Agency): The origins of the internet are rooted in ARPA.
• Experimental Start: On January $2$, $1969$, an experimental computer network was launched.
• Core Concepts of Early Architecture:
  • No Central Server: The network was designed with the concept that there would be no central server; instead, every computer in the network held equal importance and participation levels.
  • Resilience: The design ensured that even if one or two nodes were destroyed (for example, by a disaster), the functionality of the network would not be affected.
• Significant Historical Milestones:
  • $1982$: The specific term ‘internet’ began to be used.
  • $1984$: ARPANET achieved a milestone of more than $1,000$ individual computers linked as hosts.
  • $1986$: The first ‘freenet’ was created at Case Western Reserve University.
  • $1986$: The National Science Foundation (NSF) connected NSFnet to ARPANET, at which point the system became known as the Internet.
  • $1991$: The United States government permitted business agencies to connect to the internet.
  • $1995$: NSFNet terminated its network on the Internet and resumed its status exclusively as a research network.
  • $1996$: Internet$2$ was founded.
  • Today: More than $550$ million hosts are connected to the Internet.
• Modern Access: In the current era, all people can connect to the internet to improve the quality of their life and work across various aspects.

Key Figures in Internet Development

• Vinton Cerf: Known as the ‘Father of the Internet.’ He was the co-designer of the TCP/IP networking protocol.
• Tim Berners-Lee: Known as the ‘Father of the World Wide Web (WWW).’ He invented the WWW in $1989$ while working at CERN, the European Particle Physics Laboratory.

The World Wide Web (WWW)

• Definition: The World Wide Web, or the Web, is a system of interlinked hypertext and hypermedia documents that are accessed via the Internet.
• Hypertext: Text displayed on an electronic device with references (hyperlinks) to other text that a reader can access immediately, typically through a mouse click or key press.
• Hypermedia: A logical extension of hypertext that intertwines graphics, audio, video, plain text, and hyperlinks to create a non-linear medium of information.
• Internet vs. World Wide Web:
  • The Internet: A collection of networks connecting millions of businesses, government agencies, educational institutions, and individuals.
  • The WWW: The specific means used to access information over the internet. It utilizes different communication protocols and special links (hyperlinks) that allow users to jump between different places on the web.
• Web Page: A document or resource of information suitable for the Web. It is accessed via a web browser and can be displayed on monitors or mobile devices. Information is usually in HTML or XHTML format and may contain text, graphics, audio, and video.
• Web Site: A collection of related web pages and associated items.
• Web Server: A computer that delivers requested web pages to a user's computer.
• Web $2.0$: Refers to websites that provide a means for users to interact with the content and each other.

Web Browsers

• Definition: A software application intended for retrieving, presenting, and traversing information resources on the World Wide Web. It enables users to locate, view, and navigate the web.
• Types of Interfaces:
  • Graphical User Interface (GUI): Browsers that display pictures, graphics, sound, and video in addition to text (e.g., Internet Explorer, Mozilla Firefox, Google Chrome, Opera, Safari, Netscape Navigator).
  • Text-based: Browsers that display only text (e.g., Lynx or Links).
• Historical Milestone: The first web browser, Mosaic, was developed in $1991$ by Marc Andreessen.
• Microbrowsers: Web pages designed specifically for small screens on devices use microbrowsers.
• Tabbed Browsing: Allows users to open and view multiple web pages within a single browser window.

Internet Infrastructure and Governance

• Maintenance: Each organization involved is responsible only for maintaining its own individual network.
• W3C (World Wide Web Consortium): This body oversees research and establishes guidelines and standards for the Web.
• Internet$2$: A high-speed private network connecting more than $200$ universities and $115$ companies.
• Access Providers: Businesses that provide internet access to individuals and organizations, either for a fee or for free.
  • ISP (Internet Service Provider): Divided into Regional ISPs (specific geographic areas) and National ISPs (cities and towns nationwide).
  • OSP (Online Service Provider): Offers many members-only features (e.g., AOL, MSN).
  • WISP (Wireless Internet Service Provider): Provides wireless access to computers and mobile devices, sometimes requiring a wireless modem.

Protocols and Addressing

• Protocol Definition: A set of guidelines or rules for exchanging messages and transferring data between devices.
• Common Protocols:
  • HTTP: Hypertext Transfer Protocol.
  • IP: Internet Protocol.
  • FTP: File Transfer Protocol.
  • SMTP: Simple Mail Transfer Protocol.
  • NNTP: Network News File Transfer Protocol.
  • TCP: Transmission Control Protocol (typically used in conjunction with IP).
• IP Address: A unique number identifying every computer or device connected to the Internet.
• Domain Name: The text-based version of an IP address.
• TLD (Top-Level Domain): The suffix at the end of a domain name.
• DNS Server: Translates the domain name into its associated numerical IP address.

Generic Top-Level Domains (TLDs)

Search Tools and Techniques

• Search Engine: A tool used to find information related to specific topics, including images, videos, audio, publications, maps, people, blogs, and businesses.
• Subject Directory: A tool that classifies web pages into an organized set of categories.
• Widely Used Search Tools: A$9$, AlltheWeb, AltaVista, AOL Search, Ask, Bing, Cuil, Dogpile, Excite, Gigablast, Google, Lycos, MSN, Open Directory Project, WebCrawler, Yahoo!.
• Search Engine Operators:
  • Space or +: Displays hits including both specified words (e.g., art + music).
  • OR: Displays hits including at least one word from a list (e.g., dog OR puppy).
  • Parentheses ( ): Used to combine complex hits (e.g., Kalamazoo Michigan (pizza OR subs)).
  • Minus -: Excludes a word from results (e.g., automobile -convertible).
  • Quotation Marks " ": Search for an exact phrase in a specific order (e.g., "$19$th century literature").
  • Asterisk : Substitute characters as a wildcard (e.g., writer finds writer, writers, writer’s).

Types of Websites and Multimedia

• Website Categories ($13$ Types):
  1. Portal
  2. News
  3. Informational
  4. Business/Marketing
  5. Blog
  6. Wiki
  7. Online Social Network
  8. Educational
  9. Entertainment
  10. Advocacy
  11. Web Application
  12. Content Aggregator
  13. Personal
• Multimedia Components:
  • Graphic: Digital representation of non-text information (Formats: BMP, GIF, JPEG, PNG, TIFF).
  • Thumbnail: A small version of a larger graphic.
  • Animation: Appearance of motion created by a series of still images in sequence.
  • Audio: Music, speech, or sound, usually compressed to reduce file size. Transferred via streaming.
  • Video: Images displayed in motion.
  • Virtual Reality (VR): Computers used to simulate three-dimensional environments.
  • Plug-in: A program that extends the browser's capabilities.

Web Publishing and E-Commerce

• Steps of Web Publishing:
  1. Plan a Website
  2. Analyze and Design a Website
  3. Create a Website
  4. Deploy a Website
  5. Maintain a Website
• E-Commerce Categories:
  • B$2$C: Business-to-consumer.
  • C$2$C: Consumer-to-consumer.
  • B$2$B: Business-to-business.
  • M-commerce: E-commerce specifically conducted using mobile devices.

Other Internet Services

• E-mail: Transmission of messages/files via a network. Requires an e-mail program to create, send, receive, forward, store, print, and delete messages.
• Mailing List: A group of names/addresses given a single name; requires subscribing and unsubscribing.
• Instant Messaging (IM): Real-time Internet communication.
• Chat and Chat Rooms: Real-time typed conversations.
• VoIP (Voice over IP): Internet telephony allowing users to speak over the web.
• Newsgroups and Message Boards: Online areas for written discussions on specific subjects.
• FTP (File Transfer Protocol): Standard for uploading and downloading files between computers.

Step-by-Step Procedures

How a Home User's Data Travels (Cable Modem):

1. User initiates a request (e.g., requesting a web page).
2. Cable modem transfers digital signals to the home's cable television line.
3. Signals travel through lines to a central cable system shared by up to $500$ neighborhood homes.
4. Central system sends the request over high-speed fiber-optic lines to the cable operator/ISP.
5. ISP routes the request through the Internet backbone to the destination server.
6. The server retrieves the data and sends it back through the backbone to the user's computer.

How a Browser Displays a Home Page:

1. Start browser software.
2. Browser checks its ‘home page’ setting (e.g., msn.com).
3. Browser communicates with the ISP server; the server translates the domain name to an IP address (e.g., $207.68.172.234$) and sends it to the computer.
4. Browser uses the IP address to contact the web server, which then sends the home page back for formatting and display.

How E-Retail Works:

1. Customer displays the e-retailer's storefront.
2. Customer adds items to an electronic shopping cart.
3. Customer enters payment info on a secure site; info is sent to a bank.
4. Bank performs security checks and sends authorization.
5. Web server sends confirmation to the customer and processes the order.
6. Fulfillment center packages the order.
7. Shipping information is posted on the web.
8. Order is delivered and receipt is acknowledged.

Netiquette (Code of Internet Behavior)

• Golden Rule: Treat others as you would like them to treat you.
• Messaging Guidelines:
  • Keep messages brief; use proper grammar and punctuation.
  • Avoid sarcasm and humor to prevent misinterpretation.
  • Avoid offensive language and ‘flames’ (abusive messages).
  • Do not use all capital letters (considered shouting).
  • Identify ‘spoilers’ explicitly.
  • Avoid ‘spam’ (unsolicited junk mail).
• Emoticons:
  • :) Smile
  • :| Indifference
  • :o Surprised
  • :( Frown
  • :\ Undecided
• Common Abbreviations:
  • btw: by the way
  • imho: in my humble opinion
  • fyi: for your information
  • ttfn: ta ta for now
  • fwiw: for what it's worth
  • tyvm: thank you very much
• General Rules: Read the FAQ (Frequently Asked Questions); do not assume information is accurate; never read someone's private e-mail.

The Internet is a global network that connects billions of computers, allowing users to share resources like hardware, software, data, and information. The term ‘Internet’ combines ‘interconnection’ and ‘network.’ No single entity owns the Internet, and it is made up of various interconnected networks.

• History: The Internet began with the Advanced Research Projects Agency (ARPA). An experimental network started on January 2, 1969, emphasizing a decentralized structure where all computers were equal. Significant milestones include:

  • 1982: The term ‘internet’ was officially used.
  • 1984: Over 1,000 computers linked in ARPANET.
  • 1991: Businesses allowed on the Internet.
  • 1995: NSFNet ceased operation, marking a shift to commercial use.
  • Now, over 550 million hosts connect to the Internet.

• Key Figures:

  • Vinton Cerf: Known as the ‘Father of the Internet’ for co-designing TCP/IP.
  • Tim Berners-Lee: Invented the World Wide Web (WWW) in 1989.

• World Wide Web (WWW): A system of interlinked documents accessed over the Internet. Hypertext allows users to click links to jump between pages. The Web is a way to find and use information on the Internet.

• Web Browsers: Software that displays web content. Examples include Google Chrome and Firefox. The first web browser, Mosaic, was created in 1991. Web browsers can be graphical (supporting images and video) or text-based.

• Internet Structure:

  • Organizations maintain different parts of the network.
  • ISPs: Companies that provide Internet access.

• Protocols: Sets of rules for data communication, including HTTP for web pages and FTP for file transfers.

• Web Publishing: Steps include planning, designing, creating, deploying, and maintaining a website. E-commerce involves buying and selling goods online, with categories like B2C (business to consumer) and C2C (consumer to consumer).

• Netiquette: Guidelines for polite online communication, like keeping messages clear and brief, and respecting others' privacy.