Chapter 10

THE INTERNET

After completing this chapter, you will be able to:

��	Describe how the Internet works
��	Recognize how graphics, animation, audio, video, and virtual reality are used on the World Wide Web
  Identify the tools required for Web publishing
��	Describe the uses of electronic commerce (e‑commerce)
��	Explain how e‑mail, FTP, Telnet, newsgroups, mailing lists, and chat rooms work
��	Identify the rules of netiquette
��	Understand security precautions for the Internet
��	Explain how network computers are used

Today, one of the major reasons business, home, and other users purchase computers is for Internet access. Many companies and organizations assume the public is familiar with the Internet. Web addresses appear on television, in radio broadcasts, in printed newspapers magazines, and other forms of advertising. Software companies use their Web sites as a place for you to download upgrades or enhancements to software products. The government publishes thousands of informational Web pages to provide individuals with material such as legislative updates, tax forms, and e‑mail addresses for Congress members. To be successful today, you must have an understanding of the Internet. Without it, you are missing a tremendous resource for goods, services, and information. This chapter discusses the history and structure of the Internet and the various services available on the Internet.

THE INTERNET

You have learned that a network is a collection of computers and devices connected together via communications devices and media such as cables, telephone lines, modems, and satellites. The world's largest network is the Internet, which is a worldwide collection of networks that links together millions of businesses, government offices, educational institutions, and individuals. Each of these networks provides resources that add to the abundance of goods, services, and information accessible via the Internet.

The many networks that comprise the Internet, also called the Net, are local, regional, national, and international. Although each network that constitutes the Internet is owned by a public or private organization, no single organization owns or controls the Internet. Each organization on the Internet is responsible only for maintaining its own network.

Today more than 100 million users around the world connect to the Internet for a variety of reasons. Some of the uses of the Internet are as follows:

��		To access a wealth of information, news, research, and educational material
��		To conduct business or complete banking and investing transactions
��	To access sources of entertainment and leisure such as online games, magazines, and vacation planning guides
��		To shop for goods and services
��		To meet and converse with people around the world in discussion groups or chat rooms	
��		To access other computers and exchange files
��		To send messages to or receive messages from other connected users

To support these and other activities, the Internet provides a variety of services including the World Wide Web, electronic mail (e‑mail), FTP, Telnet, newsgroups, mailing lists and chat rooms. These services, along with a discussion of the history of the Internet and how the Internet works, are explained in the following pages.	

HISTORY OF THE INTERNET

Although the history of the Internet is relatively short, its growth has been explosive. The Internet has it roots in a networking project started by the Pentagon's Advanced Research Projects Agency (ARPA), which is an agency of the U.S. Department of Defense. ARPA's goal was to build a network that (1) would allow scientists at different locations to share information and collaborate 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 war. That network, called ARPANET, became functional in September 1969, effectively linking together scientific and academic researchers in the United States.

The original ARPANET was a wide area network consisting of four main computers, one each located at the University of California at Los Angeles, the Stanford Research Institute, the University of California at Santa Barbara, and the University of Utah. Each of these four computers served as the network's host nodes. In a network, a host node, or host, is any computer directly connected to the network. A host often stores and transfers data and messages on high‑speed communications lines and provides network connections for other computers.

As researchers and others realized the great benefit of using ARPANET's electronic mail to share information and notes, ARPANET underwent phenomenal growth. By 1984, ARPANET had more than 1,000 individual computers linked as hosts. (Today, more than 35 million hosts are connected to the Internet.)

To take further advantage of the high-speed communications offered by ARPANET, some organizations decided to connect entire networks to ARPANET. In 1986, for example, the National Science Foundation (NSF) connected its huge network of five supercomputer centers, called NSFnet, to ARPANET. This configuration of complex networks and hosts became known as the Internet.

Because of its advanced technology, NSFnet served as the major backbone network on the Internet until 1995. A backbone is a high‑speed network that connects regional and local networks to the Internet; other computers then connect to these regional and local networks to access the Internet. A backbone thus handles the bulk of the communications activity, or traffic, on the Internet. In 1995, NSFnet terminated its back‑bone network on the Internet to return its status to a research network. Since then, a variety of corporations, commercial firms, 	and other companies run backbone networks that provide access to the Internet.

These backbone networks, along with telephone companies, cable and satellite companies, and the government al1 contribute toward the internal structure of the Internet. Many donate resources, such as servers, communication lines, and technical specialists — making the Internet truly collaborative.

	  Even as it grows, the Internet remains a public, cooperative, and independent network. Although no single person, company, institution, or government agency controls or owns the Internet, several organizations contribute 	toward its success by advising, defining standards, and addressing other issues.

 
HOW THE INTERNET WORKS

Data sent over the Internet travels via networks and communications lines owned and operated by many companies. Various ways to connect to these networks are presented in the following sections.

Internet Service Providers and Online Services

An Internet service provider (ISP) is an organization that has a permanent Internet connection and provides temporary connections to individuals and companies for a fee. The most common ISP fee arrangement is a fixed amount, usually about $20 per month for an individual account. For this amount, many ISPs provide unlimited Internet access, while others specify a set number of access hours per month, such as 100 hours. If you spend more time on the Internet than the allotted access hours, you are charged an additional amount, based on an hourly rate.

Two types of ISPs exist: local and national. A local ISP usually provides one or more local telephone numbers to provide access to the Internet. A national ISP is a larger business that provides local telephone numbers in most major cities and towns nation‑ wide; some also provide a toll‑free telephone number. Because of their size, national ISPs offer more services and generally have a larger technical support staff than local ISPs. The most important consideration when selecting an ISP is to be sure that it provides a local telephone number for Internet access, called a point of presence (POP); otherwise, you pay long‑distance telephone bills for the time you are connected to the Internet.

Like an ISP, an online service provides Internet access, but such online services also have members‑only features that offer a variety of special content and services such as news; weather; legal information; financial data; hardware and software guides; games; and travel guides. For this reason, the fees for using an online service usually are slightly higher than fees for an ISP. Online services such as America Online and The Microsoft Network (MSN) usually have thousands of POPs all over the world and large customer and technical support staff.

Connecting to the Internet

Many users connect to the Internet through a business or school network. In this instance, their computers usually are part of a local area network (LAN) that is connected to an ISP through a high‑speed connection line leased from the local telephone company. Instead of connecting via a modem, a personal computer connects to the LAN using a network interface card (NIC), which is an expansion card that allows the computer to be networked.

When connecting from home or while traveling, individuals typically use dial‑up access to connect to the Internet. With dial‑up access, you might use your computer and a modem to dial into an ISP or online service over a regular telephone line. The computer at the receiving end, whether at an ISP or online service, also may use a modem. Dial‑up access provides an easy way for mobile and home users to connect to the Internet to check e‑mail, read the news, and access research material. Because dial‑up access uses regular telephone lines, however, the speed of the connection is limited.

Newer technologies such as Integrated Services Digital Network (ISDN) and cable modems provide an alternative to dial‑up access over regular telephone lines. ISDN provides users with faster‑speed Internet connections.

How Data Travels the Internet

Computers connected to the Internet work together to transfer data and information around the world using servers and clients. Recall that a server is a computer that manages the resources on a network and provides a centralized storage area for software programs and data. A client is a computer that can access the contents of the storage area on the server, including programs, data, and other resources. On the Internet, for example, your computer is a client that can access files and services on a variety of servers, which are called host computers.

When a client computer sends data over the Internet, the data is divided into small pieces, called packets. The data in a packet might be part of an e‑mail message, a file, a document, or a request for a file. Each packet contains the data, as well as the recipient (destination), origin (sender), and sequence information used to reassemble the data at the destination. These packets are sent along the fastest available path to the recipient's computer via devices called routers. If the most direct path to the destination is overloaded or not operating, the routers send the packets along an alternate path.

If necessary, each packet can be sent over a different path to the destination. If the packets arrive out of sequence, the destination computer uses the sequence information contained in each packet to reassemble the original message, file, document, or request. This technique of breaking a message into individual packets, sending the packets along the best route available, and then reassembling the data is called packet switching.

For a technique such as packet switching to work, all of the devices on the network must follow certain standards, or protocols. A communications protocol specifies the rules that define how devices connect to each other and transmit data over a network. The protocol used to define packet switching on the Internet is a communications protocol known as TCP/IP (transmission control protocol/Internet protocol).

The inner structure of the Internet works much like a transportation system. Just as highways connect major cities and carry the bulk of the automotive traffic across the country, several main communications lines carry the heaviest amount of traffic on the Internet. These communications lines are referred to collectively as the Internet backbone.

In the United States, the communications lines that make up the Internet backbone exchange data at several different locations. These locations, which function like a highway interchange, are one of two basic types: Network Access Points or Metropolitan Area Exchanges. Network Access Points (NAPs) and Metropolitan Area Exchanges (MAEs) are located in major cities and use high‑speed equipment to transfer data packets from one network to another.

National ISPs, sometimes called backbone providers, use dedicated lines to connect directly to the Internet backbone at one or more NAPs or MAEs. Smaller regional networks and local ISPs, by contrast, lease lines from local telephone companies to connect to national ISPs. These smaller, slower‑speed regional and local networks extend out from the backbone into regions and local communities.

Internet Addresses

The Internet relies on an addressing system much like the postal service to send data to a computer at a specific destination. Each computer location on the Internet has a numeric address called an IP (Internet protocol) address. The IP address consists of four groups of numbers, each separated by a period. The number in each group is between O and 255. For example, the numbers, 198.112.168.223, are an IP address. In general, the first portion of each IP address identifies the network and the last portion identifies the specific computer.

Because these all‑numeric IP addresses are difficult to remember and use, the Internet supports the use of a text name that represents one or more IP addresses. The text version of an IP address is called a domain name.

Every domain name contains a top‑level domain (TLD) abbreviation that identifies the type of organization that operates the site. For international Web sites, the domain name also includes a country code, which usually is placed at the end of a domain name — for countries outside the United States.

Domain names are registered in the domain name system (DNS) and are stored in Internet computers called domain name system servers (DNS servers). Recall that the Internet is based on IP addresses. Every time you specify a domain name, a DNS server translates the domain name into its associated IP address, so that data can be routed to the correct computer.

Because the rapid growth of the Internet is expected to continue, an expanded IP addressing scheme is being implemented. The new address scheme will increase the number of addresses by a factor of four and will provide added security for data transfers.

THE WORLD WIDE WEB

Although many people use the terms World Wide Web and Internet interchangeably, the World Wide Web is just one of the many services available on the Internet. The World Wide Web actually is a relatively new aspect of the Internet. While the Internet was developed in the late 1960s, the World Wide Web came into existence less than a decade ago—in the early 1 990s. Since then, however, it has grown phenomenally to become the most widely used service on the Internet.

Recall that the World Wide Web (WWW), or simply Web, consists of a worldwide collection of electronic documents that have built‑in hyperlinks to other related documents. These hyperlinks, called links, allow users to navigate quickly from one document to another, regardless of whether the documents are located on the same computer or on different computers in different countries.

An electronic document on the Web is called a Web page; it can contain text, graphics, sound, and video, as well as links to other Web pages. A collection of related Web pages that you can access electronically is called a Web site. Most Web sites have a starting point, called a home page, which is similar to a book cover or table of contents for the site and provides information about the site's purpose and content.

Each Web page on a Web site has a unique address, called a Uniform Resource Locator (URL). A URL consists of a protocol, a domain name, and sometimes the path to a specific Web page or location in a Web page. Most Web page URLs begin with http://, which stands for hypertext transfer protocol, the communications protocol used to transfer pages on the Web. You access and view Web pages using a software program called a Web browser, or browser. The more widely used Web browsers today are Microsoft Internet Explorer and Netscape Navigator.

The Web pages that comprise a Web site are stored on a server, called a Web server. A Web server is a computer that delivers (serves) requested Web pages. For example, when you enter the URL, http://www.sportsline.com/mlb/index.html in your browser, your browser sends a request to the server that stores the Web site of www.sportsline.com. The server then fetches the page named index.html and sends it to your browser.

Multiple Web sites can be stored on the same Web server. For example, many Internet service providers grant their subscribers storage space on a Web server for their personal or company Web sites.

A Webmaster is the individual responsible for developing Web pages and maintaining a Web site. Webmasters and other Web page developers create and format Web pages using hypertext markup language (HTML), which is a set of special codes that define the placement and format of text, graphics, video, and sound on a Web page. Because HTML can be difficult to learn and use, many user-friendly tools exist for Web publishing, which is the development and maintenance of Web pages. HTML and other Web publishing techniques are discussed later in this chapter.

Search Engines

No single organization controls additions, deletions, and changes to Web sites, which means no central menu or catalog of Web site content and addresses exists. Several companies, however, maintain organized directories of Web sites to help you find information on specific topics. The companies provide a software program, called a search engine, which 	helps you locate Web sites, Web pages, and Internet files.

Multimedia on the Web

Most Web pages include more than just formatted text and links. In fact, some of the more exciting Web developments involve multimedia. A Web page that incorporates color, sound, motion, and graphics with text has much more appeal than one with text on a gray background. Combining text, audio, video, animation, and sound brings a Web page to life; increases the types of information available on the Web; expands the Web's potential uses; and makes the Internet a more entertaining place to explore. Although multimedia Web pages often require more time to download because they contain large files such as video or audio clips, the pages usually are worth the wait.

Most browsers have the capability of displaying basic multimedia elements on a Web page. Sometimes, however, your browser might need an additional program, called a plug‑in or helper application, which extends the capability of the browser. A plug‑in runs multimedia elements within the browser window, while a helper application runs multimedia elements in a window separate from the browser. Plug‑ins and helper applications can be downloaded, or copied, at no charge from many sites on the Web. In fact, Web pages that use multimedia elements often include links to Web sites that contain the required plug‑in or helper. Some browsers include commonly used plug‑ins, such as Shockwave, which is required for viewing many multimedia Web pages.

Some of the multimedia on the Web is developed in Java, which is a programming language specifically designed by Sun Microsystems for use on the Internet. Developers use Java to create small programs called applets that can be downloaded and run in a browser window. Applets can be used by just about any type of computer. Similar to an apples, an ActiveX control is a small program that can be downloaded and run in a browser, thus adding multimedia capabilities to Web pages. Although Microsoft initially developed ActiveX controls, programmers can develop ActiveX controls using Java as well as other programming languages.

The following sections discuss how graphics, audio, animation, video, and virtual reality are used on the Web.

GRAPHICS Graphics were the first media used to enhance the text‑based Internet. The introduction of graphical Web browsers allowed Web page developers to incorporate illustrations, logos, and other images into Web pages. Today, many Web pages use colorful graphical designs and images to convey messages.

Graphics files on the Web must be saved in a certain format. The two more common file formats for graphical images on the Web are JPEG and GIF. A JPEG (pronounced JAY‑peg) file, which stands for Joint Photographic Experts Group, is a graphical image saved using compression techniques to reduce the file size for faster downloading from the Web. When you create a JPEG image, you can specify the image quality to reach a balance between image quality and file size. The JPEG format often is used for scanned photographs, artwork, and other images that include smooth color variations.

A graphical image saved as a GIF (pronounced jiff or giff) file, which stands for Graphics Interchange Format, also is saved using compression techniques to reduce its file size for downloading. The GIF format works best for images with only a few distinct colors, such as line drawings, single‑color borders, and simple cartoons. The technique used to compress GIF files (called LZW compression), however, is patented, which means companies that make products using the GIF format must obtain a license. (Most Web users or businesses that include GIFs in their Web pages are not required to obtain a license.)

A patent‑free replacement for the GIF, the PNG format, has been developed and approved by the World Wide Web Consortium as an Internet graphics standard. The PNG (pronounced ping) format, which stands for portable network graphics, also is a compressed file format that supports multiple colors and resolutions.

The Web contains thousands of image files on countless subjects, many of which can be downloaded free and used for noncommercial purposes. Because graphics files can be time consuming to download, some Web sites use thumbnails on their pages. A thumbnail is a small version of a larger graphical image that you usually can click to display the full‑sized image.

ANIMATION Animation is the appearance of motion that is created by displaying a series of still images in rapid sequence. Animated graphics can make Web pages more visually interesting or draw attention to important information or links. For example, text that is animated to scroll across the screen, called a marquee (pronounced marKEE), can serve as a ticker to display stock updates, news, sports scores, or weather. Animation often is used in Web‑based games; some animations even contain links to a different page.

One popular type of animation, called an animated GIF, is created using computer animation and graphics software to combine several images into a single GIF file. You also can create applets or ActiveX controls that include animation, or you simply can download many already‑developed animations from the Web.

	AUDIO Simple Web audio applications 	consist of individual sound files that must be downloaded completely before they can be 	played. As with graphics files, these sound files must be saved in a certain format. Two 	common formats used for audio files on the Internet are WAV and AU. More advanced Web audio applications use streaming audio. Streaming is the process of transferring data in a continuous and even flow, which allows users to access	and use a file before it has been transmitted completely. Streaming is important because most users do not have fast enough Internet connections to download a large multimedia file quickly. Streaming audio, enables you to listen to the sound (the data) as it downloads to your computer. Many radio and television stations use streaming audio to broadcast music, interviews, talk shows, sporting events, music videos, news, live concerts, and other segments. One accepted standard for transmitting audio data on the Internet is RealAudio, which is supported by most current Web browsers.

Web‑based audio can be used for Internet telephone service, also called audio-conferencing and Internet telephony, which enables you to talk to other people over the Web. Internet telephony uses the Internet (instead of a public telephone network) to connect a calling party and one or more called parties. Internet telephony thus allows you to talk to friends or colleagues for just the cost of your Internet connection. As you speak into a computer microphone, Internet telephone software and your computer's sound card digitize and compress your conversation and then transmit the digitized audio over the Internet to the called parties. Software and equipment at the receiving end reverse the process so the receiving parties can hear what you have said, just as if you were on a telephone.

Some of today's Web browsers include software such as CoolTalk and Microsoft NetMeeting, which supports Internet telephony. In addition to Internet telephony, these products typically offer additional services such as a whiteboard to display drawings, diagrams, and other graphics; chat tools to type text messages; and even videoconferencing so you can see images of the meeting participants.

VIDEO Like audio, simple Web video applications consist of individual video files, such as movie or television clips, that must be downloaded completely before they can be played on your computer. Because video files often are large and can take a long time to download, these video clips usually are quite short.

As with streaming audio, streaming video allows you to view longer or live video images as they are downloaded to your computer. A widely used standard for transmitting video data on the Internet is RealVideo. Like RealAudio, RealVideo is supported by most current Web browsers.

Streaming video also allows you to conduct Internet videoconferences, which work much like Internet telephony. As you are filmed by a video camera, videoconferencing software and your computer's video capture card digitize and compress the images and sounds. A popular video compression standard is defined by the Motion Picture Experts Group (MPEG). Files in the MPEG format typically have an .mpg extension.

This compressed data is divided into packets and sent over the Internet. Equipment and software at the receiving end assemble the packets, decompress the data, and present the image and sound as video. As with traditional videoconferencing, live Internet videoconferences can be choppy and blurry depending on the speed of the slowest communications link. As mentioned earlier, many products that support Internet telephony also have videoconferencing capabilities, thus allowing for face‑to‑face conversations over the Internet.

VIRTUAL REALITY Virtual reality (VR) is the simulation of a real or imagined environment that appears as a three‑dimensional (3‑D) space. On the Web, VR involves the display of 3‑D images that you can explore and manipulate interactively. Most Web‑based VR applications are developed using virtual reality modeling language, or VRML (pronounced VER‑mal), which is a language that defines how 3‑D images display on the Web. Using VRML, a developer can create an entire 3‑D site, called a VR world, that contains infinite space and depth. A VR world, for example, might show a room with furniture. You can walk through such a VR room by moving your pointing device forward, backward, or to the side. To view a VR world, you need a VRML browser or a VRML plug‑in to a Web browser.

VR often is used for games, but it has many practical applications as well. Science educators can create VR models of molecules, organisms, and other structures for students to examine. Companies can use VR to showcase products or create advertisements. Architects can create VR models of buildings and rooms so they can show their clients how a completed construction project will look before it is built.

Until recently, when you wanted information from a Web site, you requested, or pulled, the information from the site by entering a URL in your browser or clicking a link. Some of today's browsers support push technology, in which Web‑based content is downloaded automatically to your computer at regular intervals or whenever the site is updated. You can choose to have the entire site or just a portion of it, such as the latest news, pushed to your computer. In Microsoft Internet Explorer, for example, push technology can be implemented through channels. A channel is a pre-selected Web site that automatically can send updated information. You can choose to view the information immediately or access it later. Push technology thus saves you time by delivering information at regular intervals, without your having to request it.

Another advantage to push technology is that once Web content has been pushed to your computer, you can view it whether you are online or offline—that is, when you are not connected to the Internet. With push technology, the contents of one or more Web sites are downloaded to your hard disk while you are online, thus making them available for browsing while you are offline. Offline browsing is ideal for mobile users because they do not always have access to the Internet.

The concept of using push and pull technologies to broadcast audio, video, and text information is called webcasting. With webcasting, you receive customized Web content that is updated regularly and automatically. The information you receive is based on the preferences you choose, such as selecting certain channels and setting times for updates.

ELECTRONIC COMMERCE

When you conduct business activities online, you are participating in electronic commerce, also known as e‑commerce. These activities include shopping, investing, and any other venture that uses either electronic money (e‑money) or electronic data interchange. Electronic data interchange (EDI) is the transmission of business documents or data over communication lines. Many companies are using EDI on the Internet for buying, selling, or trading because it eliminates paperwork and increases response times.

One major advantage of e‑commerce is that consumers can purchase directly from businesses, eliminating the middleman. For example, instead of visiting a computer retailer to purchase a computer, you now can order one designed to your specifications, right from the manufacturer's Web site. This practice enables businesses to provide goods and services at a lower cost.

		Electronic money (e‑money), also called digital cash, is a means of paying for goods and services over the Internet. With one method, you purchase digital certificates from a certificate authority (CA), which is an authorized company or person that issues and verifies digital certificates. A digital	certificate is an electronic credential that ensures a user is legitimate and the transfer of confidential materials is secure. Many banks,	for example, allow you to purchase digital certificates that represent cash. Each digital	cash certificate is assigned a unique number that represents an amount of money, just like the unique numbers on real currency. 

Once you have the digital cash certificate, you can purchase goods or services over the Web. To do this, you transfer the digital cash certificate to the vendor, who then deposits the certificate number in a bank or transfers it to another vendor. Just like paper money, digital cash is reusable and anonymous; that is, the vendor has no information about the buyer. Because of this, many users prefer to pay with e‑money instead of a credit card. Currently, no standard exists for e‑money, and many companies offer various electronic payment schemes for use on the Internet. A variation on e‑money is electronic credit or an electronic wallet, which is a credit‑card payment scheme for use on the Web. With electronic credit, a small program, called a wallet, stores your address and credit card information on your computer's hard disk. When you purchase something using electronic credit, you can choose from any of the credit cards in your wallet, and that information is	transferred from your computer to the vendor's computer. Your credit card information is	encrypted when it is stored on your computer and sent over communication lines. Encryption is the conversion of data into a form that cannot be easily understood by unauthorized people.

WEB PUBLISHING

Before the advent of the Web, the means to share opinions and ideas with others easily and inexpensively was limited to classroom, work, or social environments. Generating an advertisement or publication that could reach a massive audience required a lot of expense. Today, businesses and individuals can convey information to millions of people by using Web pages. Individual Web pages are sometimes called personal Web pages.

As mentioned earlier in this chapter, Web pages are created and formatted using hypertext markup language (HTML), which is a set of special codes used to format a file for use as a Web page. These codes, called tags, specify how the text and other elements display in a browser and where the links lead. Your Web browser translates the document with HTML tags into a functional Web page.

��	The development and maintenance of Web pages, called Web publishing, is fairly easy as long as you have the proper tools.

��	To incorporate pictures in your Web pages, you could use a digital camera to take digital photographs or a scanner to convert your existing photographs and other graphics into digital format. It also would be beneficial to have a collection of clip art and/or other images, which you can download from the Web or purchase on CD‑ROM or DVD‑ROM.

��	With a sound card, you can add sounds to your Web pages. A microphone allows you to include your voice in a Web page.

��	To incorporate videos, you could use a video capture card and a video camera. Or, you can purchase a video digitizer to capture still photographs from videos.

��	If you are comfortable using HTML tags, you can create an HTML document using any text editor or standard word processing software. You must save the HTML document as an ASCII file with an .htm or.html extension, instead of as a formatted word processing document.

��	To develop a Web page, however, you do not have to be a computer programmer— or even learn more than basic HTML. Instead, you can generate HTML tags with Web page authoring software — or just your word processing software. Many current word processing packages include Web page authoring features that help you to create basic Web pages that contain text and graphics.

��	To create more sophisticated Web pages that include video, sound, animation, and other special effects, you can use Web page authoring software such as Adobe PageMill or Microsoft FrontPage. Both new and experienced users can create fascinating Web sites with this software.

Web page authoring software hides the complexity of HTML instructions used to format a Web page and allows a Web page developer to focus on Web page design and style. Many Web page authoring products provide templates and wizards, along with collections of design elements such as bullets, backgrounds, patterns, fonts, and graphics, to assist you with Web page development.

After your Web pages are created, you store them on a Web server. Many ISPs and online services provide their customers with a Web address and 1 to 10 MB of storage on a Web server without an additional charge. If your ISP does not include this service, companies called Web hosting services provide storage for your Web pages for a reasonable monthly fee. The fee charged by a Web hosting service varies based on factors such as the amount of storage your Web pages require, whether your pages use streaming or other multimedia, and whether the pages are personal or for business use.

Once you have created a Web page and located a Web server to store it, you need to upload the Web page, or copy it, from your computer to the Web server. A common procedure used to upload files is FTP, which is discussed later in this chapter.

To help others locate your Web site, you should register it with various search engines. Doing so ensures that your site will appear in the results returned for searches on keywords related to your site. Many search engines allow you to register your URL and keywords without cost.

Registering your site with the various search engines, however, can be an extremely time‑consuming task. Instead, you can use a submission service, which is a Web‑based business that usually offers free registration of your site with several search engines or a registration package in which you pay to register with hundreds of search engines.

In addition to supplying a title for your site, the URL, and a site description, the submission service probably will require you to identify several features of your site, such as whether the site is commercial or personal; a category and subcategory; and search keywords. For example, if your Web site business sells greeting cards, you could register under the Products and Services subcategory in the Business and Economy category, and specify keywords such as greeting cards, birthday cards, and anniversary cards.

OTHER INTERNET SERVICES

Although the World Wide Web is the most talked about service on the Internet, many other Internet services are used widely. These include e‑mail, FTP, Telnet, newsgroups, mailing lists, and chat rooms. Each of these services is discussed in the following sections.

E‑mail

E‑mail (electronic mail) is the transmission of messages and files via a computer network. E‑mail was one of the original services on the Internet, enabling scientists and researchers working on government‑sponsored projects to communicate with colleagues at other locations. Today, e‑mail quickly is becoming a primary communication method for both personal and business use.

Using an e‑mail program, you can create, send, receive, forward, store, print, and delete messages. To receive messages, you need an e‑mail address, which is a combination of a user name and a domain name that identifies a user. When you receive an e‑mail message, the message is placed in your mailbox. A mailbox is a storage location usually residing on the computer that connects you to the Internet, such as the server operated by your Internet service provider (ISP). The server that contains the mailboxes often is called a mail server. Most ISPs and online services provide an Internet e‑mail program and a mailbox on a mail server as a standard part of their Internet access services.

When you send a message, the message is transmitted according to a communications protocol called SMTP (simple mail transfer protocol). The mail server uses SMTP to determine how to route the message through the Internet and then sends the message. When the message arrives at the recipient's mail server, the message is transferred to a POP or POP3 server. POP (Post Office Protocol) is a communications protocol used to retrieve e‑mail from a mail server. The POP server holds the message until the recipient retrieves it with his or her e‑mail software. The newest version of POP is POP3, or Post Office Protocol 3.

Most e‑mail programs allow you to send messages that contain graphics, audio and video clips, and computer files, as attachments. These attachments must be converted, or encoded, to binary format so they can be sent over the Internet and then decoded when the recipient retrieves them. Most e‑mail software includes encoding schemes that make it possible for attachments to arrive at the recipient's computer in the same format in which they left the sender's computer.

FTP

FTP (file transfer protocol) is an Internet standard that allows you to exchange files with other computers on the Internet. For example, if you click a link on a Web page that begins to download a file to your hard disk, you probably are using FTP.

An FTP server is a computer that allows users to upload and download files using FTP. An FTP server contains one or more FTP sites. An FTP site is a collection of files including text, graphics, audio, video, and program files that reside on an FTP server. Some FTP sites limit file transfers to individuals who have authorized accounts (user names and passwords) on the FTP server. Many FTP sites allow anonymous FTP, whereby anyone can transfer some, if not all, available files. Microsoft, for example, has an FTP site that uses anonymous FTP to allow customers to download software updates, manuals, and other files. Many program files on anonymous FTP sites are freeware or public domain software, while others are shareware.

To view or use a file on an FTP site, you first must download it to your computer. In most cases, you click the file name to begin the download procedure. Large files on FTP sites often are compressed to reduce storage space and download transfer time. Before you use a compressed file, you must expand it with a decompression program, such as WinZip. Such programs usually are available for download from the FTP site.

In some cases, you may want to upload a file to an FTP site. For example, if you create personal Web pages, you will want to post them on a Web server. To do this, many Web servers require you to upload the files using FTP. To upload files from your computer to an FTP site, you use an FTP program. Many Internet service providers include an FTP program as part of their Internet access service; you also can download FTP programs from the Web.

Telnet

Telnet is a program or command that enables you to connect to a remote computer on the Internet. To make a Telnet connection to the remote computer, you enter a user name and password. Once connected, your computer acts like a terminal directly linked to the remote computer. Telnet access to many remote computers is free, while others are accessed for a fee. For convenience, some remote computers provide the Telnet program.

Some uses of Telnet include connecting to a remote computer to access databases, directories, and library catalogs. Online databases may contain research results, and directories containing lists of information such as people and organizations.

The widespread use of Internet service providers and Web browsers, however, has reduced the need to log in directly to remote computers using Telnet. Many libraries, for example, have converted their library databases to allow Web‑based access.

	Newsgroups

A newsgroup is an online area in which users conduct written discussions about a particular subject. To participate in a discussion, a user sends a message to the newsgroup, and other users in the newsgroup read and reply to the message. The entire collection of Internet newsgroups is called Usenet, which contains thousands of newsgroups on a multitude of topics. Some major topic areas include news, recreation, business, science, and computers.

A computer that stores and distributes newsgroup messages is called a news server. Many universities, corporations, ISPs, online services, and other large organizations have a news server. Some newsgroups require you to enter your user name and password to participate in the discussion. These types of newsgroups are used when the messages on the newsgroup are to be viewed only by authorized members, such as students taking a college course.

To participate in a newsgroup, you use a program called a newsreader, which is included with most browsers. The newsreader enables you to access a newsgroup to read a previously entered message, called an article. You also can add an article of your own, a process called posting. A newsreader also keeps track of which articles you have and have not read.

Newsgroup members frequently post articles as a reply to another article—either to answer a question or to comment on material in the original article. These replies may cause the author of the original article, or others, to post additional articles related to the original article. The original article and all subsequent related replies are called a thread or threaded discussion. A thread can be short‑lived or continue for some time, depending on the nature of the topic and the interest of the participants.

Using a newsreader, you can search for newsgroups discussing a particular subject, such as a type of musical instrument, brand of sports equipment, or employment opportunities. To help you determine what topics are discussed in a particular newsgroup, newsgroups are identified using a hierarchical naming system, with a major category divided into one or more subcategories. Each subcategory is separated by a period. If you like the discussion in a particular newsgroup, you can subscribe to it, which means its location is saved in your newsreader so you can access it easily in the future.

In some newsgroups, when you post an article, it is sent to a moderator instead of immediately displaying on the newsgroup. The moderator reviews the contents of the article and then posts it, if appropriate. Called a moderated newsgroup, the moderator decides if the article is relevant to the discussion. The moderator may choose to edit or discard inappropriate articles. For this reason, the content of a moderated newsgroup is considered more valuable.

Mailing Lists

A mailing list is group of e‑mail names and addresses given a single name. When a message is sent to a mailing list, every person on the list receives a copy of the message in his or her mailbox. To add your e‑mail name and address to a mailing list, you subscribe to it; to remove your name, you unsubscribe from the mailing list. Some mailing lists are called LISTSERVs, named after a popular mailing list software product.

Thousands of mailing lists exist on a variety of topics in areas of entertainment, business, computers, society, culture, health, recreation, and education. To locate a mailing list dealing with a particular topic, you can search for the keywords, mailing lists or LISTSERVs, using your Web browser.

Chat Rooms

A chat is a real‑time typed conversation that takes place on a computer. Real‑time means that you and the people with whom you are conversing must be online at the same time. When you enter a line of text on your computer screen, your words display on one or more participant's screens.

A chat room refers to the communications medium, or channel, that permits users to chat with each other. Anyone on the channel can participate in the conversation, which usually is specific to a particular topic. Each discussion is assigned a different channel.

To start a chat session, you connect to a chat server through a chat client, which is a program on your computer. Today's browsers usually include a chat client. If yours does not, you can download a chat client from the Web. Some chat clients are text‑based, such as IRC (Internet relay chat) and ichat, while others, such as Microsoft Chat, support graphical and text‑based chats.

Once you have installed a chat client, you then can create or join a conversation on the chat server to which you are attached. The channel name should indicate the topic of discussion. The person who creates a channel acts as the channel operator and has responsibility for monitoring the conversation and disconnecting anyone whom becomes disruptive. Operator status can be shared or transferred to someone else.

Several Web sites exist for the purpose of conducting chats. Some chat sites even allow participants to assume the role or appearance of a fictitious character.

Portals

A portal is a Web site designed to offer a variety of Internet services from a single, convenient location. Most portals offer the following free services: search engine; local, national, and worldwide news, sports, and weather; reference such as yellow pages and maps; shopping malls; e‑mail; and chat rooms. Some portals also provide Internet access.

Popular portals include AltaVista, Excite, InfoSeek, Lycos, Microsoft Internet Start, Netscape Netcenter, Snap, and Yahoo! The goal of these portals is to be designated as your browser's starting Web page.

NETIQUETTE

Netiquette, which is short for Internet etiquette, is the code of acceptable behaviors users should follow while on the Internet; that is, the conduct expected of individuals while online. Netiquette includes rules for al] aspects of the Internet, including the World Wide Web, e‑mail, FTP, Telnet, newsgroups, and chat rooms.

USING THE INTERNET: COOKIES AND SECURITY

While it is a vast and exciting resource, the Internet also is a public place, and as with all other public places, you should use common sense while there. The following sections explain guidelines for the use of cookies and security precautions for your consideration while using the Internet.

Cookies

Webcasting, e‑commerce, and other Web applications often rely on cookies to track information about viewers, customers, and subscribers. A cookie is a smal1 file that a Web server stores on your computer. Cookie files typically contain data about you, such as your user name or viewing preferences. Some Web sites send a cookie to your browser, which stores it on your computer's hard disk. The next time you visit the Web site, your browser retrieves the cookie from your hard disk and sends the data in the cookie to the Web site. Web sites use cookies for a variety of purposes.

Web sites that allow for personalization often use cookies to track user preferences. On such sites, you may be asked to fill in a form requesting personal information, such as your name and site preferences. A news site, for example, might allow you to customize your viewing preferences to display business and sports news only. Your preferences are stored in a cookie on your hard disk.

Online shopping sites generally use cookies to keep track of items in your shopping cart. This way, you can start an order during one Web session and finish it on another day in another session.

Some Web sites use cookies to track how regularly you visit a site and the Web pages you visit while at the site.

Web sites may use cookies to target advertisements. Your interests and browsing habits are stored in the cookie.

Although many believe that cookies allow other Web sites to read information on your computer, a Web site can read data only from its own cookie file; that is, it cannot access or view any other data on your hard disk — including another cookie file. Some Web sites do, however, sell or trade information stored in your cookie to advertisers — a practice many believe to be unethical. If you do not want your personal information being distributed, you should limit the amount of information you provide to a Web site. You can set your browser to accept cookies automatically, prompt you if you wish to accept a cookie, or disable cookie use altogether.

Internet Security

Even with netiquette guidelines, the Internet opens up the possibility for improper behaviors and content. For example, amidst the wealth of information and services on the Internet, some content may be inappropriate for certain people. Some Web sites, newsgroups, or chat rooms, for instance, contain content or discussions that are unsuitable for children. To assist parents with these types of issues, many browsers include software that can screen out unacceptable content. You also can purchase Internet filtering software, which allows parents, teachers, and others to block access to certain materials on the Internet.

Confidentiality is another important consideration on the Internet. For example, when shopping online, you should be sure that confidential or personal information such as your credit card number is encrypted during transmission. Reputable companies have secure servers that automatically encrypt this type of information while it is being transmitted.

One way to identify a secure Web page is to see if its URL begins with https://, instead of http://. Many browsers today also include encryption software that allows you to encrypt e‑mail messages or other documents. Attaching a digital signature to a document or message verifies your identity to the recipient, which is especially critical for e‑commerce.

NETWORK COMPUTERS

For some applications, including many of the Internet services, a personal computer has more capability than the application requires. Jobs that primarily involve entering transactions or looking up information in a database—even viewing pages on the Web— do not require floppy disks, CD‑ROMs, or large hard disks. These extra components contribute to both the cost and complexity of a personal computer; the more complex a computer is, the more expensive it is to maintain. As the costs of owning, operating, and maintaining a personal computer increase, many users are turning to network computers.

A network computer (NC), sometimes called a thin‑client computer, is a less expensive version of a personal computer designed specifically to connect to a network, especially the Internet. Most network computers cannot operate as a stand‑alone computer; that is, they must be connected to a network to be functional. Network computers typically rely on the network for storage and, therefore, usually do not have a hard disk or CD‑ROM drive.

A specific type of network computer used in business applications is the network personal computer, or NetPC, which was designed cooperatively by Microsoft and Intel. A NetPC primarily relies on the server for software and storage but does have a hard disk for storing some data and programs. A NetPC can run Java and other programs such as Microsoft Windows applications.

Low‑cost network computers are well suited for use in the home, especially if a potential home user plans to purchase a computer only for Internet access. A network computer for the home, sometimes called a set‑top box, is a device that incorporates Internet access into a television set. To keep the cost down, manufacturers have eliminated many standard computer features, such as any type of disk drive or monitor. Instead, your television set serves as the monitor. A set‑top box is placed on top of your television set and allows you to access the Internet and navigate Web pages using a device that looks like a remote control. If you want to use the device to enter e‑mail, you can use an optional wireless keyboard.

=== End of Chapter 10 ===