XML (eXtensible Markup Lanaguage)
....technology of choice

We may often wonder why standards come and go like seasons , first it was SGML then came HTML and now it is XML.

XML appears to be different as it has a wide support from a lot of companies,trying to obey this standard. Altough it is never safer to make predictions, especially when computers are concerned,it now seems almost certain that XML,Extensible Markup Language will play a big part in the Internet's future,especially the way data is stored and displayed.

What is XML?

XML is a project of the World Wide Web Consortium (W3C), and the development of the specification is being supervised by their XML Working Group Xml is not a single ,predefined mark up language, it's a meta language that lets you design your own mark up.

XML like HTML is descended from SGML and as its name suggests it is designed to be extensible, allowing new tags to be created as needed,thus being more powerful than HTML.User can create new tags and attributes unlike HTML, which is restricted to a set of pre-defined tags.
It includes all the important features of SGML, but leaves back all the drawbacks of it.Thus XML retains the power and flexibility of SGML without any complexity.

XML is a markup language for documents containing structured information.Structured information contains both content (words, pictures, etc.) and some indication of what role that content plays (for example, content in a section heading has a different meaning from content in a footnote, which means something different than content in a figure caption or content in a database table, etc.). Almost all documents have some structure.

A markup language is a mechanism to identify structures in a document.

The XML specification defines a standard way to add markup to documents.

XML users can create there own tags which actually relate to their content .

Let us take an example of a person's name .

<name>
     <first_name>Steve</first_name>
     <middle_initial>N</middle_initial> 
     <last_name>Robinson</last_name>
</name>

Here you can see that the tags contain information about their contents. The <name> tag is the root tag , <first_name> tag tells you that the element's contents relate to the persons firstname,similarly the <middle_initial> tag contains the persons initial and the <last_name> tag contains the persons lastname details respectively. So the above piece of xml tags contains information about a person marked up with tags that describe their contents.

If there were entries like this for each person then it could be used in a number of ways ,including:List of contacts.An address tag can be added to the same to have more information about the person. You can extend the same by adding more tags with respect to what kind of information you like to gather of a particular person.