XML and Its Impact

How important is XML? Almost four years ago, the Gartner Group, an Internet research company, said that 80% of business-to-business (also known as B2B ) traffic used XML. XML is much like HTML and in some ways is identical.

The author of XML code can define and use, on-the-fly , brand new command tags that are also available to other Web pages. In defining new XML command tags, you use the extensible portion of XML.

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 to place Web page elements.

Consider the following possible XML section from a Web page:

 <CARMAKE>Swifty</CARMAKE> <CARMODEL>Dove</CARMODEL> <ENGINEPARTNO>546-32Xs</ENGINEPARTNO> <WHOLESALE>,039</WHOLESALE> <SUGGESTEDRETAIL>,483</SUGGESTEDRETAIL> 

Over time, industries will begin to standardize their XML tags. Therefore, <ENGINEPARTNO> might be standardized by automobile Web-site designers to designate any automobile manufacturer's engine part number. As other automobile Web developers standardize and use <ENGINEPARTNO> (and its corresponding ending tag of </ENGINEPARTNO> ), Web pages can be combined, borrowed, and used as the basis of other Web pages that also contain such parts .

When learning XML, you would not learn a <CARMAKE> tag because no such tag exists. As soon as a Web site uses <CARMAKE> , however, the tag is defined and should be used in that context. As a Web designer, you will learn the standard XML tags being used for the type of Web site you are developing. Your XML tags then define data categories, not actual data specifics.

One problem at this time is that XML is too new for globally agreed upon definitions to exist. Even within industries, one company might create XML tags that differ greatly from another's. The move toward organization will come only as companies that support XML begin to agree on a standard and that standard grows. For example, if your company's Web site is to interact with a vendor's XML-based Web site, one of you must adopt the other's XML tags or you must put into place a combined system. This agreement process will continue and grow as more companies move to XML.

For the first time, Web search engines can begin to search across industries for categories of items instead of performing time-consuming , tedious , and resource- grabbing searches for specific text embedded in Web pages. A search engine could scour Web page tags for the exact tag <ENGINEPARTNO> to locate specific engine parts for automobile manufacturers quickly instead of wasting search time and resources scanning nonautomobile Web-site inventories.

HTML has a defined set of formatting and hyperlink tags, and you could very easily learn all of them. XML is defined as Web designers use it. You'll never learn all the XML tags, because new tags will continue to be developed as long as the language is in use.