The best example is that XML can store data, or distribute data. Much like a database, you can create your own fields and records, and most of all, it's not propriatery, therefore, you don't need specific programs to read it or write it. Try RSS, that's a good example of XML.
http://en.wikipedia.org/wiki/Rss
http://en.wikipedia.org/wiki/XML

It's useful if you want to store data with ten times the space and three times the verbosity you need. It's also useful if you want to transform your data with XSLT into other XML documents, but this time with twenty times the verbosity you'd get in any other language. XML is useful since it's simple and there are XML parsing libraries lying around waiting for you to use them, in many programming languages. Never mind that handy facilities for parsing and manipulating hierarchal expressions were built into Lisp more than a quarter century ago...

As a standard way of formatting data, it's best used for communication between foreign programs, and perhaps for human-readable configuration files. But it's not good to use an XML document as if it were a database, unless you enjoy slowing your computer down.

Hi..arya..

HTML can only be used to display data in computer browsers....think of a situation where you have to display the same data in a Palm Top !!!!!

So if you use XML there instead of HTML ...your new device will be able to understand it..

I hope it helps....

Rajesh C Medackel. TVM, India