Getting a grasp of how XML works will help you see how it aims to be a complete solution for creating Web applications. XML stands for eXtensible Markup Language. Like HTML, XML derives from the granddaddy of all markup languages: SGML (Standard Generalized Markup Language). SGML is a metalanguage, or a system for defining markup languages such as HTML. XML is also a metalanguage, a subset of SGML designed for use on the Web. As with SGML, you can use XML to define different markup language..
