The applications for XML are broad. Multiple agencies have created the XML-based FedStats.net a Web site that provides a gateway to statistics from more than 100 federal agencies. The National Archives and Records Administration plans to convert records into XML-based documents as part of its Electronic Records Archive Program, so they can be read hundreds of years from now. The XML standard has some underlying components that make it work. XML tags define elements of the document such as a name or Social Security number.
Tags draw on XML document type definitions, which describe the content and structure of a document.
For example, an electronic payment might include customer name, address, account number, balance and bill number. Microsoft Corp. s Word. XML schemas take DTDs a step further. They are more complete and coherent documents necessary for more advanced data exchange efforts. They provide a means for defining the structure, content and semantics of XML documents.