What is XML? >> Scott Klarr

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What is XML?

Jan 27, 2008 at 9:35 pm - 0 Comments

What is XML for?

XML stands for extensible markup language. There is a lot of hype over XML and it is talked about as if its a revolutionary programming language, but really it is not. It is nothing more than a way to structure data so that it can be processed and used on any platform or in any app (that is designed to use XML, that is) and in fact, it has been around for 10 years.

XML is a markup language which means it is based around organizing data into hierarchies. Think of it as a filing cabinet. On the very base of organization, you have say 3 drawers; one for bank statements, one for bills, and the other for personal documents. Now, lets open up the bank statements drawer. The next level of organization is tabs separating years. One section of the drawer is for 2006, then 2007, then 2008. Going one step further into the organization hierarchy would be a folder for each month of the year. Lets example how that may look in XML format

<?xml version="1.0"?>
<cabinet>
 <drawer name="Bank Statments">
  <group name="Years">
   <year id="2008">
    <month name="january" id="1">08' January statements go in here</month>
    <month name="february" id="2">08' Februrary statements go in here</month>
   </year>
   <year id="2007">
    <month name="january" id="1">07' January statements go in here</month>
    <month name="february" id="2">07' Februrary statements go in here</month>
   </year>
  </group>
 </drawer>
 <drawer name="Bills">
  Bill information in here
 </drawer>
 <drawer name="Personal">
  Personal information in here
 </drawer>
</cabinet>

XML does not have a specific list of tags that you can or cannot use like say, XHTML, which is also a markup language; instead, you have complete control over the tag names, tag properties, and tag values. There are also other means of formating data for transportation, such as JSON, but XML is the most widely used because of its flexibility in storing data in small and large scales.