What is the primary transfer protocol used by the World Wide Web for delivering Web content that have been formatted using HTML?

The Internet

The Internet is the largest implementation of client/server computing and internetworking, linking hundreds of thousands of individual networks and 1 billion people worldwide.

Individuals connect to the Internet in two ways: through local Internet service providers (ISPs) and through their business firms.

The Internet is based on the TCP/IP networking protocol suite. Every computer is assigned a unique Internet Protocol (IP) address, which is currently four strings of numbers ranging from 0 to 255, as in the address 207.46.250.119. The Domain Name System (DNS) is a system for converting IP addresses into names, such as google.com. DNS has a hierarchical structure which specifies a root domain, top-level domains, second-level domains, and host computers at the third level.

Figure 7-8

FIGURE 7-8 THE DOMAIN NAME SYSTEM The Domain Name System is a hierarchical system with a root domain, top-level domains, second-level domains, and host computers at the third level.

Internet traffic moves over trunk lines, transcontinental high-speed backbone networks, typically owned by long-distance telephone companies (network service providers) or national governments. Local connection lines are owned by regional telephone and cable television companies in the US that lease access to ISPs, private companies, government institutions, and retail users.

Figure 7-9

FIGURE 7-9 INTERNET NETWORK ARCHITECTURE The Internet backbone connects to regional networks, which in turn provide access to Internet service providers, large firms, and government institutions. Network access points (NAPs) and metropolitan area exchanges (MAEs) are hubs where the backbone intersects regional and local networks and where backbone owners connect with one another. MAEs are also referred to as Internet Exchange Points.

Internet policies are established by several organizations and governmental bodies, including the Internet Architecture Board (IAB), the Internet Corporation for Assigned Names and Numbers (ICANN), the Internet Network Information Center (InterNIC), the Internet Engineering Task Force (IETF), the Internet Society (ISOC), and the World Wide Web Consortium (W3C). These agencies influence government agencies, major network owners and ISP.

Everyone who uses the Internet pays some fee�hidden or otherwise�to maintain the network. For example, each organization and business firm pays for its own networks and its own local Internet connection services, a part of which is paid to the long-distance trunk line owners

Because the number of addresses using the existing IP addressing (IPv4) is limited to 4.5 billion addresses, the Internet Engineering Task Force adopted a new Internet Protocol Version 6 (IPv6), which uses a 128-bit addressing scheme which produces 3.4 x 1038 addresses.

The existing Internet has many shortcomings chief among which are poor security, no service level guarantees, no differential service, no differential pricing, and bandwidth limitations that would prevent the emergence of wide-scale Internet television or Internet video distribution. Internet2 and Next-Generation Internet (NGI) are consortia representing 200 universities, private businesses, and government agencies in the United States that are working on a new, robust, high-bandwidth version of the Internet.

The Internet is based on client/server technology. Client platforms include PCs, cell phones, PDAs, handheld devices, and information appliances. Users of the Internet control what services they access through client applications on their computers such as Web browsers. Internet services include e-mail, electronic discussion groups (Usenet groups and LISTSERV), chatting, and instant messaging, Telnet, File Transfer Protocol (FTP), and the World Wide Web. Each Internet service is implemented by one or more software programs.

Figure 7-10

FIGURE 7-10 CLIENT/SERVER COMPUTING ON THE INTERNET Client computers running Web browser and other software can access an array of services on servers over the Internet. These services may all run on a single server or on multiple specialized servers.

Web pages are formatted with graphics, text, and dynamic links using Hypertext Markup Language (HTML). Web pages are requested by clients and delivered by Web servers using the Hypertext Transfer Protocol (HTTP). HTTP is the first set of letters at the start of every Web address, followed by the domain name, the directory path to the requested document, and the document name. The address typed in to a browser to locate a file, including the directory path and the document name together, is called a Uniform Resource Locator (URL). A Web server is software for locating and managing stored Web pages. The most common Web server today is Apache HTTP Server.

Users can find information on the Internet using search engines. The first search engines were simple keyword indexes of all the pages they visited. Contemporary search engines use more complex models for finding relevant information. Google ranks search results based on the relevance, or popularity, of each page. Web sites for locating information such as Yahoo!, Google, and MSN have become so popular and easy to use that they also serve as major portals for the Internet, as well as major shopping tools. In search engine marketing, search results display both listings to a query as well as advertisements related to the search query. The paid, sponsored advertisements are the fastest-growing form of Internet advertising.

Figure 7-11, Figure 7-12

FIGURE 7-11 MAJOR WEB SEARCH ENGINES Google is the most popular search engine on the Web, handling nearly 50 percent of all Web searches. Sources: http://searchenginewatch.com, accessed August 19, 2006 and Kevin J. Delaney, �Search Engines Find a Role for Humans,� The Wall Street Journal, May 11, 2006.

FIGURE 7-12 HOW GOOGLE WORKS The Google search engine is continuously crawling the Web, indexing the content of each page, calculating its popularity, and storing the pages so that it can respond quickly to user requests to see a page. The entire process takes about one-half second.

Intelligent agent shopping bots search the Web for pricing and availability of products specified by the user and return a list of sites that sell the item, along with pricing information and purchase links.

Web 2.0 refers to second-generation, interactive Internet-based services, such as:

• Mashups: Software services that enable users and system developers to mix and match content or software components to create something entirely new
• Blogs: Informal yet structured Web site where subscribing individuals can publish stories, opinions, and links to other Web sites of interest
• RSS: RSS (Rich Site Summary, or Really Simple Syndication) technology pulls specified content from Web sites and feeds it automatically to users' computers, where it can be stored for later viewing
• Wikis: Collaborative Web sites where visitors can add, delete, or modify content on the site, including the work of previous authors

Internet networking technology is used by organizations to create private networks called intranets and extranets, intranets extended to authorized vendors and customers to facilitate communication and business transactions. Intranets and extranets are protected from unauthorized visits by firewalls�security systems with specialized software to prevent outsiders from entering private networks.

In addition to e-mail, Internet-based tools that today's businesses use for communication and coordination include:

• Chat: Chatting enables two or more people on the Internet to hold live, interactive conversations.
• Instant messaging: A type of chat service that enables participants to create
• their own private chat channels.
• Usenet newsgroups: Worldwide discussion groups posted on Internet electronic bulletin boards
• Groupware: Software products used by individuals and teams working at different locations for writing and commenting on group projects, sharing ideas and documents, conducting electronic meetings, tracking the status of tasks and projects, scheduling, and sending e-mail.
• Electronic conferencing: Web conferencing and collaboration software allow participants to view and modify documents and slides, write or drawn on an electronic whiteboard, or share their thoughts and comments using chat or voice conferencing.
• Internet telephony: Voice over IP (VoIP) technology uses the IP to deliver voice information in digital form using packet switching, avoiding the tolls charged by local and long-distance telephone networks

Figure 7-13

FIGURE 7-13 HOW IP TELEPHONY WORKS An IP phone call digitizes and breaks up a voice message into data packets that may travel along different routes before being reassembled at the final destination. A processor nearest the call�s destination, called a gateway, arranges the packets in the proper order and directs them to the telephone number of the receiver or the IP address of the receiving computer.

• Virtual private network (VPN): A secure, encrypted, private network that has been configured within a public network to take advantage of the economies of scale and management facilities of large networks, such as the Internet.

Figure 7-14

FIGURE 7-14 A VIRTUAL PRIVATE NETWORK USING THE INTERNET This VPN is a private network of computers linked using a secure �tunnel� connection over the Internet. It protects data transmitted over the public Internet by encoding the data and �wrapping� them within the Internet Protocol (IP). By adding a wrapper around a network message to hide its content, organizations can create a private connection that travels through the public Internet.

Which of following protocol is HTTP built upon?

What is TCP IP's own messaging system for email?

Which of these protocols were used by the browser in fetching and loading the webpage?

Which of the following terms describes a computer or a software application that requests services from a server on the Internet group of answer choices?