Fundamentally, the Web is a set of protocols that operate over the Internet and that can be extended to operate over private, internal networks. Three essential technologies define the World Wide Web today and set out to characterize the communication between a Web client (an individual user’s computer) and a Web server (the computer containing files that individual users access) connected over a TCP/IP network.
The first is the Internet standard protocol referred to as Hypertext Transfer Protocol (HTTP), which was developed in the late 1980s. HTTP is different from FTP in that it was designed to provide a standard way of viewing documents as well as transferring them from one computer to another. The second technology of the Web is often referred to as the language of the Web—Hypertext Markup Language (HTML). HTML is the document format for Web documents or pages. Traditional word processors use a proprietary method for representing document attributes such as spacing and fonts. HTML uses directives, or tags, to specify format, leaving the actual formatting to the client. HTML is a subset of Standard Generalized Markup Language (SGML), providing codes used to format hypertext linking between documents. The HTML standard is guarded closely by the World Wide Web Consortium (W3C), which is headed by Tim Berners-Lee, the founder of the World Wide Web.
HTML documents can contain references to drawings, pictures, sound, and other multimedia content. HTML documents can also refer to other documents by a Uniform Resource Locator (URL). A URL is the location of a particular Internet resource. A possible URL for an HTML document might be http://www.mycompany.com/sales/august.html.
The ability of an HTML document to contain a reference, or link, to another HTML document creates a collection of interlinked documents. This collection of documents is referred to as the World Wide Web. But keep in mind that the World Wide Web is not the Internet. It is merely an application that uses the features that the Internet provides.
The ease of use and practical nature of the World Wide Web have been the main force behind the explosion of Internet use over the last decade. Over 50 million documents exist on the World Wide Web, and the number of documents continues to increase dramatically.
Web protocols (specifically HTTP and HTML) have gone through at least three phases to date and continue to metamorphose. The first phase provided no more than the ability to publish information by means of a hypertext model. Each section of the document could point to other sections in different documents on the same or different servers at different locations on different platforms—navigation was totally ad hoc and nonlinear.
Of course, “static” publishing was OK, but it didn’t take long for developers to recognize the potential for “dynamic” publishing. Some information is static, but certain elements are real-time. This provision is referred to as “dynamic” publishing—the need to tie static information in with live data. The Web also allows for “interactive,” or “active,” publishing. An interactive site can canvass input from the user by means of, for example, a form containing fields, and the data collected can then be processed and a response can be created dynamically. If you want to use the Web to collect customer information, you can write a Web application that creates an appropriate fill-in form and puts the data gathered into tables. If your customers are having trouble finding specific information within your organization, write a Web application that provides an interface that lets users search your data.
Interactive Web sites are seen as a key to providing support for electronic commerce and transaction processing. This, of course, will require programming beyond HTML and Common Gateway Interfaces (CGI).