1. Technology

What is XML?


Question: What is XML?

XML stands for Extensible Markup Language. It was developed at the World Wide Web Consortium, by a group of people who wanted to improve on HTML and SGML. It was defined as a formal specification in February 1998.

XML is not a true markup language, but rather a system for defining other languages. In other words, XML is a language for writing markup languages.

How XML Works

  1. A markup language like HTML defines the look and feel of your document in a reader or browser. HTML includes elements like FONT, B, and I to define how the document looks.
  2. However, the browser itself doesn't know or care what the document is. If you write a recipe in HTML, the browser will not know that there is a semantic difference between your recipe and a list of stock quotes.
  3. If you use XML to markup your document, you tell the user-agent (the Web browser or computer accessing the XML document) that it was looking at a recipe or stock quotes.
  4. The XML markup would include definitions of the parts of the recipe or the stock information.
  5. XML doesn't have markup for recipes or stocks. You write the markup yourself and include it in the document.

©2014 About.com. All rights reserved.