What is XML?

XML is the Extensible Markup Language. It is designed to improve the functionality of the Web by providing more flexible and adaptable information identification.

It is called extensible because it is not a fixed format like HTML (a single, predefined markup language). Instead, XML is actually a `metalanguage' --a language for describing other languages--which lets you design your own customized markup languages for limitless different types of documents.

XML is a standard, simple, self-describing  way of encoding both text and data so that content can be processed with relatively little human intervention and exchanged across diverse hardware, operating systems, and applications.

In brief, XML offers a widely adopted standard way of representing text and data in a format that can be processed without much human or machine intelligence. Information formatted in XML can be exchanged across platforms, languages, and applications, and can be used with a wide range of development tools and utilities.

Look at this simple example defining a FAQ:


	<?xml version="1.0"?>
	<!DOCTYPE question-list SYSTEM "faq.dtd">
	<?xml-stylesheet type="text/xml" href="faq.xsl"?>

	<FAQ-LIST>
		<QUESTION>
			<QUERY>Question goes here</QUERY>
			<RESPONSE>Answer goes here.</RESPONSE>
		<QUESTION>
		</QUESTION>
			<QUERY>Another question goes here.</QUERY>
			<RESPONSE>The answer goes here.</RESPONSE>
		</QUESTION>
	</FAQ-LIST>