Absolute Beginner's Guide to Programming, Third Edition

XML and Its Impact

How important is XML? The Gartner Group, an Internet research company, says that 80% of business-to-business (also known as B2B) traffic uses XML. XML is much like HTML, and in many ways is identical. An XML listing includes standard HTML command tags, but XML command tags are far more numerous.

An XML coder can define and use, on-the-fly, brand-new command tags that are also available to other Web pages. In defining your own XML command tags, you are using the extensible portion of XML. Code examples throughout the rest of this chapter will help show how the XML coder does this.

Whereas HTML describes the format of a Web page, XML describes the content of a Web page. XML does more than just tell the Web browser where and how ...