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Chapter 2: The Internet & World Wide Web
0BJECTIVES:
After completing this chapter, you will be able to:
1. Explain how to access and connect to the Internet
2. Explain how to view pages and search for information on the Web
3. Describe the types of Web sites
4. Identify the steps required for Web publishing
5. Describe the types of e-commerce
6 Explain how e-mail, FTP newsgroups and message boards, mailing lists, chat rooms, Instant messaging, and Internet telephony work
7. Identify the rules of netiquette
CONTENTS:
THE INTERNET
HOW THE INTERNET WORKS
Connecting to the Internet
Access Providers
How Data Travels the Internet
Internet Addresses
THE WORLD WIDE WEB
Browsing the Web
Web Addresses
Navigating Web Pages
Searching for Information on the Web
Types of Web Sites
Evaluating a Web Site
Multimedia on the Web
Web Publishing
E-Commerce
OTHER INTERNET SERVICES
E-Mail
FTP
Newsgroups and Message Boards
Mailing Lists
Chat Rooms
Instant Messaging
Internet Telephony
NETIQUETTE
CHAPTER SUMMARY
COMPANIES ON THE CUTTING EDGE
Google
Yahoo!
TECHNOLOGY TRAILBLAZERS
Tim Berners-Lee
Meg Whitman
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One of the major reasons business, home, and other users purchase computers is for Internet access The Internet also called the Net, is a worldwide collection of networks that links millions of businesses, government agencies, educational institutions, and individuals. Through the Internet, society has access to global information and instant communications.
Today, more than one billion users around the world connect to the Internet for a variety of reasons, some of which are shown in Figure 2-1. The World Wide Web and e-mail are two of the more widely accessed Internet services. Other services include chat rooms, instant messaging, and Internet telephony.
The Internet has its roots in a networking project started by an agency of the U.S. Department of Defense. The goal was to build a network that (1) allowed scientists at different locations to share information and work together on military and scientific projects and (2) could function even if part of the network were disabled or destroyed by a disaster such as a nuclear attack. That network, called ARPANET, became functional in September 1969, linking scientific and academic researchers across the United States.
The original network consisted of four main computers, one each located at the University of California at Los Angeles, the University of California at Santa Barbara, the Stanford Research Institute, and the University of Utah. Each computer served as a host on the network. A host or server is any computer that provides services and connections to other computers on a network. By 1984, the network had more than 1,000 individual computers linked as hosts. Today, more than 200 million hosts connect to this network, which became known as the Internet.
FIGURE 2-1 Users around the world connect to the Internet to access the Web, send e-mail messages, chat with a group, or have a private conversation with an online friend(s) or family member(s).
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The Internet consists of many local, regional, national, and international networks. Both public and private organizations own networks on the Internet. These networks, along with telephone companies, cable and satellite companies, and the government, all contribute toward the internal structure of the Internet.
Each organization on the Internet is responsible only for maintaining its own network. No single person, company, institution, or government agency controls or owns the Internet. The World Wide Web Consortium (W3C), however, oversees research and sets standards and guidelines for many areas of the Internet. About 350 organizations from around the world are members of the W3C.
Data sent over the Internet travels via networks and communications media owned and operated by many companies. The following sections present various ways to connect to these networks on the Internet.
Employees and students often connect to the Internet through a business or school network. Many homes and some small businesses use dial-up access to connect to the Internet. Dial-up access takes place when the modem in your computer uses a standard telephone line to connect to the Internet. A dial-up connection, however, is slow-speed technology.
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Some home and small business users are opting for higher-speed Internet connections through DSL, cable television, radio signals, or satellite. DSL (digital subscriber line) is a technology that provides high-speed Internet connections using regular telephone lines. A cable modem allows access to high-speed Internet services through the cable television network. Fixed wireless high-speed Internet connections use an antenna on your house or business to communicate with a tower location via radio signals. A satellite modem communicates with a satellite dish to provide high-speed Internet connections via satellite.
In most cases, DSL, cable television, fixed wireless, and satellite connections are always on, that is, connected to the Internet the entire time the computer is running. With dial-up access, by contrast, you must establish the connection to the Internet.
Mobile users access the Internet using a variety of technologies. Most hotels and airports provide dial-up or high-speed Internet connections. Wireless Internet access technologies enable mobile users to connect easily to the Internet with notebook computers, Tablet PCs, PDAs, smart phones, and smart watches while away from a telephone, cable, or other wired connection.
FAQ 2-1: How many people have high-speed Internet access?
According to a recent study, 55 percent of adult Americans access the Internet using high-speed connections at home or at work. About 40 percent of home users have high-speed Internet access. The main reason users switch to high-speed access is they are frustrated with the slow speeds of dial-up access. For more information, visit scsite.com/ dcf2e/ch2/faq and then click High-Speed Internet.
An access provider is a business that provides individuals and companies access to the Internet free or for a fee. The most common fee arrangement for an individual account is a fixed amount, usually about $10 to $25 per month for dial-up access and $40 to $99 for higher-speed access. For this fee, many providers offer unlimited Internet access. Others specify a set number of access hours per month. With the latter arrangement, the provider charges extra for each hour of connection time that exceeds an allotted number of access hours.
Users access the Internet through ISPs, online service providers, and wireless Internet service providers. An ISP (Internet service provider) is a regional or national access provider. A regional ISP usually provides Internet access to a specific geographic area. A national ISP is a business that provides Internet access in cities and towns nationwide. National ISPs usually offer more services and have a larger technical support staff than regional ISPs. Examples of national ISPs are AT&T Worldnet Service and EarthLink.
In addition to providing Internet access, an online service provider (OSP) also has many members-only features. These features include special content and services such as news, weather, legal information, financial data, hardware and software guides, games, travel guides, e-mail, photo communities, online calendars, and instant messaging. The fees for using an OSP sometimes are slightly higher than fees for an ISP. The two more popular OSPs are AOL (America Online) and MSN (Microsoft Network).
A wireless Internet service provider (WISP) is a company that provides wireless Internet access to users with wireless modems or access devices or Internet-enabled mobile computers or devices. Internet-enabled mobile devices include PDAs, smart phones, and smart watches. Examples of wireless Internet service providers include AT&T Wireless, GoAmerica, T-Mobile, and Verizon Wireless.
Computers connected to the Internet work together to transfer data and information around the world. Several main transmission media carry the heaviest amount of traffic on the Internet. These major carriers of network traffic are known collectively as the Internet backbone.
In the United States, the transmission media that make up the Internet backbone exchange data at several different major cities across the country. That is, they transfer data from one network to another until it reaches its final destination (Figure 2-2).
For more information. visit scsite.com/dcf2e/ ch2lweblink and then click Internet Backbone.
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FIGURE 2-2 HOW A HOME USER’S DATA MIGHT TRAVEL THE INTERNET USING A CABLE MODEM CONNECTION
The Internet relies on an addressing system much like the postal service to send data to a computer at a specific destination. An IP address, short for Internet Protocol address, is a number that uniquely identifies each computer or device connected to the Internet. The IP address usually consists of four groups of numbers, each separated by a period. In general, the first portion of each IP address identifies the network and the last portion identifies the specific computer.
These all-numeric IP addresses are difficult to remember and use. Thus, the Internet supports the use of a text name that represents one or more IP addresses. A domain name is the text version of an IP address. Figure 2-3 shows an IP address and its associated domain name. As with an IP address, the components of a domain name are separated by periods.
FIGURE 2-3 The P address and domain name for the Google Web site,
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In Figure 2-3 on the previous page, the corn portion of the domain name is called the top-level domain. Every domain name contains a top-level domain, which identifies the type of organization associated with the domain. Figure 2-4 lists current top-level domains. For international Web sites outside the United States, the domain name also includes a country code. In these cases, the domain name ends with the country code, such as au for Australia or for fr France.
When you specify a domain name, a server translates the domain name into its associated IF address so data can be routed to the correct computer. This server is an Internet server that usually is associated with an Internet access provider.
Test your knowledge of pages 50 through 54 in Quiz Yourself 2-1.
Instructions: Find the true statement below. Then, rewrite the remaining false statements so they are true.
1. An access provider is a business that provides individuals and companies access to the Internet free or for a fee.
2. A WISP is a number that uniquely identifies each computer or device connected to the Internet.
3. An IP address, such as www.google.com, is the text version of a domain name.
4 Dial up access takes place when the modem in your computer uses the cable television network to connect to the Internet.
Quiz Yourself Online: To further check your knowledge of accessing and connecting to the Internet, visit scsite.com/dcf2e/ch2/quiz and then click Objective 1.
The World Wide Web (WWW), or Web, a widely used service on the Internet, consists of a worldwide collection of electronic documents. Each electronic document on the Web, called a Web page, can contain text, graphics, audio (sound), and video. Additionally, Web pages usually have built-in connections to other documents. A Web site is a collection of related Web pages and associated items, such as documents and pictures, stored on a Web server. A Web server is a computer that delivers requested Web pages to your computer.
A Web browser, or browser, is application software that allows users to access and view Web pages. To browse the Web, you need a computer that is connected to the Internet and that has a Web browser. The more widely used Web browsers for personal computers are Internet Explorer, Netscape, Mozilla, Opera, and Safari.
FIGURE 2-4 With the dramatic growth of the Internet during the last few years, seven new top-level domains recently have been adopted and nine additional domains are being evaluated.
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With an Internet connection established, you start a Web browser. The browser retrieves and displays a starting Web page, sometimes called the browser’s home page. Figure 2-5 shows how a Web browser displays a home page.
The more common usage of the term, home page, refers to the first page that a Web site displays. Similar to a book cover or a table of contents for a Web site, the home page provides information about the Web site’s purpose and content. Often it provides connections to other documents, Web pages, or Web sites, which can be downloaded to a computer or mobile device. Downloading is the process of a computer receiving information, such as a Web page, from a server on the Internet. Depending on the speed of your Internet connection and the amount of graphics involved, a Web page download can take from a few seconds to several minutes.
FIGURE 2.5 HOW A WEB BROWSER DISPLAYS A HOME PAGE
Step 1: Click the Web browser program name to start the Web browser software.
Step 2: The Web browser looks up its home page setting, in this case, msn.com.
Step 3: The Web browser communicates with a server maintained by your Internet access provider. The server translates the domain name of the home page to an IP address and then sends the IP address to your computer.
Step 4: The Web browser uses the P address to contact the Web server associated with the home page and then requests the home page from the server. The Web server sends the home page to the Web browser, which formats the page for display on your screen.
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A Web page has a unique address, which is called a URL (Uniform Resource Locator) or Web address. For example, the home page for the San Diego Zoo Web site has a Web address of http://www.sandiegozoo.org. A Web browser retrieves a Web page, such as the zoo’s home page, using its Web address.
If you know the Web address of a Web page, you can type it in the Address box at the top of the browser window. If you type the Web address http://www.sandiegozoo.org/wap/condor/home.html in the Address box and then press the ENTER key, the a Web page about condors at the San Diego Zoo (Figure 2-6).
As shown in Figure 2-6, a Web address consists of a protocol, domain name, and sometimes the path to a specific Web page or location on a Web page. Many Web page addresses begin with http://. The http, which stands for Hypertext Transfer Protocol, is a set of rules that defines how pages transfer on the Internet.
To help minimize errors, most current browsers and Web sites do not require the http:// and www portions of the Web address. For example, typing sandiegozoo.org/wap/condor/home.html, instead of the entire address, still accesses the Web site.
When you enter the Web address, sandiegozoo.org/wap/condor/home.html in the Web browser, it sends a request to the Web server that contains the www.sandiegozoo.org Web site. The server then retrieves the Web page named home.html in the wap/condor/ path and delivers it to your browser, which then displays the Web page on the screen.
For information about useful Web sites and their associated Web addresses, read the Making Use of the Web feature that follows this chapter.
FIGURE 2-6 After entering the Web address http://www.sandiegozoo.org/ wap/condor/home.html in the Address box, this Web page at the San Diego Zoo Web site is displayed. Notice the www portion of the domain name does not appear in the Address box after the Web page downloads.
FAQ 2-2 How many Web pages does the average user visit in a month?
More than one thousand. This and other interesting average Web usage statistics are in the table below. For more information, visit scsite.com/dcf2e/ch2/faq and then click Web User Statistics.
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Most Web pages contain links. A link, short for hyperlink, is a built-in connection to another related Web page or part of a Web page. Links allow you to obtain information in a nonlinear way. That is, instead of accessing topics in a specified order, you move directly to a topic of interest.
Branching from one related topic to another in a nonlinear fashion is what makes links so powerful. Some people use the phrase, surfing the Web, to refer to the activity of using links to explore the Web.
On the Web, a link can be text or an image. Text links may be underlined and/or displayed in a color different from other text on the Web page. Pointing to, or positioning the pointer on, a link on the screen typically changes the shape of the pointer to a small hand with a pointing index finger. The Web page shown in Figure 2-7 contains a variety of link types, with the pointer on one of the links.
Each link on a Web page corresponds to another Web address. To activate a link, you click it, that is, point to the link and then press the left mouse button. Clicking a link causes the Web page associated with the link to be displayed on the screen. The linked object might be on the same Web page, a different Web page at the same Web site, or a separate Web page at a different Web site in another city or country. Read Looking Ahead 2-1 for a look at the next generation of browsing.
LOOKING AHEAD 2-1: Internet Speeds into the Future
The Internet of the future will be much larger and faster. According to some Internet experts, in the next 20 years, Web surfers will be able to browse more than 250 million Web sites.
This increase in volume will be based, in part, on Internet2. This not-for-profit project develops and tests advanced Internet technologies for research, teaching, and learning. lnternet2 members include more than 206 universities, 60 companies, and the U.S. government. Their goal is to change the current Internet’s inefficiencies, such as relieving bottlenecks.
Recently, lnternet2 researchers broke a speed record by sending data from Los Angeles to Geneva, Switzerland, at a speed that is nearly 10,000 times faster than the average home high-speed Internet connection. For more information, visit scsite.com/dcf2e/ch2/looking and then click lnternet2.
The Web is a global resource of information. One primary use of the Web is to search for specific information. The first step in successful searching is to identify the main idea or concept in the topic about which you are seeking information. Determine any synonyms, alternate spellings, or variant word forms for the topic. Then, use a search tool to locate the information.
The two most commonly used search tools are subject directories and search engines. A subject directory classifies Web pages in an organized set of categories, such as sports or shopping, and related subcategories. A search engine is a program that finds Web sites and Web pages.
FIGURE 2-7 This Web page contains various types of links: text that is underlined, text in a different color, and images.
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Some Web sites offer the functionality of both a subject directory and a search engine. Yahoo! and Google, for example, are widely used search engines that also provide a subject directory. To use Yahoo! or Google, you enter the Web address (yahoo.com or google.com) in the Address box in a browser window. The table in Figure 2-8 lists the Web addresses of several popular general- purpose subject directories and search engines.
FIGURE 2-8 Many subject directories and search engines allow searching about any topic on the Web.
SUBJECT DIRECTORIES A subject directory provides categorized lists of links arranged by subject. Using this search tool, you can locate a particular topic by clicking links through different levels, moving from the general to the specific. Figure 2-9 shows how to use Yahoo!’s subject directory to search for information about Bob Hope.
FIGURE 2-9 HOW TO USE A SUBJECT DIRECTORY: (Page 58/9)
Step 1: Type the search engine’s Web address (in this case, google.com) in the Address box in the Web browser and then press the ENTER key.
Step 2: When the Yahoo! home page is displayed, point to the scroll box on the side of the screen.
Step 3: Drag the scroll box downward to display the Web Site Directory area of the Web page. Point to the Entertainment link.
Step 4: Click the Entertainment link to display the Entertainment page. Scroll down to the CATEGORIES area, if necessary, and then point to the Comedy link.
Step 5: Click the Comedy link to display the Comedy page. In the CATEGORIES area, point to the Comedians link.
Step 6: Click the Comedians link to display the Comedians page. Scroll down to the SITE LISTINGS area if necessary, and then point to Hope, Bob (1903-2003).
Step 7: Click the Hope, Bob (1903-2003) link to display the Hope, Bob (1903-2003) page. Scroll down to the SITE LISTINGS area, if necessary, and then point to the Bob Hope and American Variety link.
Step8: Click the Bob Hope and American Variety link to display the Bob Hope and American Variety Web page, which contains a variety of links to specific information about Bob Hope. After you click one of these links, click the Home button to display this home page.
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SEARCH ENGINES A search engine is particularly helpful in locating Web pages about certain topics or in locating specific Web pages for which you do not know the exact Web address. Instead of clicking through links, search engines require that you enter a word or phrase, called search text, that define the item about which you want information. Figure 2-10 shows how to use the Google search engine to search for the phrase, Bob Hope television career.
The results shown in Step 3 include about 535,000 links to Web pages, called hits, that reference Bob Hope’s television career. Each hit in the list has a link that, when clicked, displays an associated Web site or Web page. Most search engines sequence the hits based on how close the words in the search text are to one another in the Web page titles and their descriptions. Thus, the first few links probably contain more relevant information.
FIGURE 2-10 HOW TO USE A SEARCH ENGINE
Step 1: Type the search engine’s web address (in this case, google.com) in the Address box in the Web Browser and then press the ENTER key.
Step 2: When the Google home page is displayed, type Bob Hope television career as the search text and then point to the Google Search button.
Step 3: Click the Google Search button. When the results of the search are displayed, scroll through the links and read the descriptions.
Step 4: Click the Bob Hope on TV link to display a Web page about Bob Hopes television career
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If you enter a phrase with spaces between the words in the search text, most search engines return links to pages that include all of the words. Techniques you can use to improve your Web searches include the following:
• Use specific nouns and put the most important terms first in the search text.
• Use the asterisk (*) to substitute characters in words. For example, retriev* returns retrieves, retrieval, retriever, and any other variation.
• Use quotation marks to create phrases so the search engine finds the exact sequence of words.
• List all possible spellings, for example, email, e-mail.
• Before using a search engine, read its Help information.
• If the search is unsuccessful with one search engine, try another.
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