XML is a universal, extensible data markup language. It's a neutral, uncompiled language that machines use to generate, store and share information in a human-readable format. It has been fairly dubbed "digital baking soda", because it has so many uses. There's hardly a software platform in existence that doesn't employ or support XML in some fashion or other.

It does make a webpage more dynamic, if used responsibly.

XML is the backbone of future internet

XML (EXtensible Markup Language) is a markup language patterned to carry data, not to exhibit data. XML tags are never predefined and you need to define your own XML tags. XML is only plain text. Software that can manage plain text can also manage XML.

XML's set of tools assists the programmers in developing web pages but its usefulness goes much beyond that. XML, combined with other standards, enables you to evaluate the content of a document separately from its formatting, turning it easier to reuse that particular content in other applications. Most significantly, XML offers a basic syntax that can be utilized to share information between various types of computers, different applications, and various organizations without requiring to pass through manifold layers of conversion.

When XML is combine with javascript, you have a dynamic page.

XML is a data transfer format.

Nothing more.