Chapter 24: Browsing the World Wide Web with Internet Explorer

What Is the World Wide Web?

The World Wide Web (usually just referred to as "the Web") is a collection of millions of files stored on thousands of computers (called Web servers) all over the world. These files represent text documents, pictures, video, sounds, programs, interactive environments, and just about any other kind of information that has ever been recorded in computer files. It is probably the largest and most diverse collection of information ever assembled.

What unites these files is a system for linking one file to another and transmitting them across the Internet. HTML codes allow a file to contain links to related files. Such a link (also called a hyperlink) contains the information necessary to locate the related file on the Internet. When you connect to the Internet and use a Web browser program like Internet Explorer, you can read, view, hear, or otherwise interact with the Web without paying attention to whether the information you are accessing is stored on a computer down the hall or on the other side of the world. A news story stored on a computer in Singapore can link you to a stock quote stored in New York, a picture stored in Frankfurt, and an audio file stored in Tokyo. The combination of the Web servers, the Internet, and your Web browser assembles this information seamlessly and presents it to you as a unified whole. This system of interlinked text, called hypertext, was first described in the 1960s by Theodor H. Nelson, but it took thirty years for it to be widely used in the form of the World Wide Web, which was invented by Tim Berners-Lee at CERN, a particle physics lab in Geneva, Switzerland in 1990.

By following links, you can get from almost any Web document to almost any other Web document. For this reason, some people like to think of the entire Web as being one big document. In this view, the links just take you from one part of the document to another.

An intranet is an internal network that uses the same communication protocols as the Internet, but is limited to a specific group, usually the employees in one company. Some organizations create private versions of the World Wide Web on their intranets so that access to their Web pages is limited to employees of that organization.

What Is HTML?

Hypertext Markup Language (HTML) is the universal language of the Web. It is a language for laying out pages that are capable of displaying all the diverse kinds of information that the Web contains. A Web browser, at the most basic level, is a program that reads and interprets HTML.

While various software companies own and sell HTML reading and writing programs, no one owns the language HTML itself. It is an international standard, maintained and updated by a complicated political process that so far has worked remarkably well. The World Wide Web Consortium (W3C), at http://www.w3.org, manages the HTML standard.

What Is a URL?

When the pieces of a document are scattered all over the world, but you want to display them seamlessly to a person who could be anywhere else in the world, you need a very good addressing system. Each file on the Internet has an address, called a Uniform Resource Locator (URL), also sometimes called an Internet address or Web address. For example, the URL of the ESPN Web site is http://espn.go.com.The first part of a URL (the part before the first colon) specifies the transfer protocol, the method that a computer needs to use to access this file. Most Web pages are accessed with the Hypertext Transfer Protocol (HTTP, the language of Web communication), which is why Web addresses typically begin with http (or its secure, encrypted versions, https or shttp). The http:// at the beginning of a Web page's URL is so common that it is assumed as the default protocol by modern browsers. If you simply type espn.go.com into the address window of Internet Explorer, the browser fills in the http:// for itself. In common usage, the http:// at the beginning of a URL is left out.

The rest of the address denotes the Web page, but might not tell you where its files are actually located. Whether ESPN's Web server is in Los Angeles or Bangkok is invisible from its URL. Information about which Web server is responsible for answering requests for which URLs is contained in a huge database that the Web servers themselves are constantly updating. As users, we don't need to deal with this level of detail, and that's a good thing. The World Wide Web would be much less usable if sports fans had to learn a new set of URLs every time ESPN got a new computer.

What Are Internet Keywords?

URLs can be hard to remember, so systems of keywords have been devised to allow easier access to most popular Web sites. So, for example, you can get to CNN's Web site by typing "cnn" into Internet Explorer's Address box.

Unlike URLs, however, Internet keywords are not standardized. Netscape Navigator, another Web browser, uses a keyword system that has evolved from AOL's, while Internet Explorer uses Real Names' keywords. Other browsers might use other systems or none at all. The more popular sites usually have the same keyword in all systems, but there are occasional discrepancies. Also, no keyword system is complete. Every page on the Web has a URL, but only a (comparative) handful have their own keywords.

What Are Web Pages and Web Sites?

A Web page is an HTML document that is stored on a Web server and has a URL so that it can be accessed via the Web.

A Web site is a collection of Web pages belonging to a particular person or organization. The home page is the "front door" of the site and is set up to help viewers find whatever is of interest to them on that site. The URL of the home page also serves as the URL of the Web site.

For example, the URL of Microsoft's home page is http://microsoft.com. From the home page, you can get to Microsoft's Web pages about Windows XP at http://microsoft.com/windowsxp.