As a power user or developer, chances are you have at least heard of XML. XML is to data what Hypertext Markup Language (HTML) is to displaying Web pages in a browser. While XML describes the data to be used, HTML describes how information is to be presented on a page. Another big difference between the two is that although HTML is primarily for the Web, XML can be used anywhere data is to be utilized. This includes single systems on a desktop, multiple business systems, or utilizing data over the Internet.
The World Wide Web Consortium (W3C), creator of HTML, first met in 1996. It is also the W3C who sets the standards for XML.
XML is a data file standard. Where the format is agreed upon, the actual commands (tags) used will depend on the technology, system, or development language utilizing the data. There are technologies commonly used by applications that take advantage of XML, a common one being XML documents. An XML document can consist of a single table or an entire database. A good example of various systems that use XML documents are the Office applications. The majority of them can both import and export XML, including Word. You can see an example of exporting XML in this chapter in the next section.
As with the HTML, various XML files use tags. However, that is all you specify in XML, what the data is. You are not specifying how the data looks. One difference between HTML and XML is that XML has much stricter requirements for creating ...