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Introduction to XML

What is XML?

  • XML (eXtensible Markup Language) is a markup language.
  • XML is designed to store and transport data.
  • XML was released in late 90’s. It was created to provide an easy to use and store self-describing data.
  • XML became a W3C Recommendation on February 10, 1998.
  • XML is designed to be self-descriptive.
  • XML is designed to carry data, not to display data.
  • XML tags are not predefined. You must define your own tags.
  • XML is platform independent and language independent.

Self-descriptive data are the data that describe both their content and their structure.


XML will not replace HTML in the near future, but it introduces new possibilities by adopting many successful features of HTML.

There are three important features of XML that make it useful in a variety of systems and solutions:

  • XML is extensible: XML allows you to create your own self-descriptive tags, or language, that fits your application.
  • XML carries the data, does not present it: XML allows you to store data regardless of how it will be presented.
  • XML is a public standard: XML was developed by an organization called the World Wide Web Consortium (W3C) and it is available as an open standard.

XML Usage

XML can be used in several ways:

  • XML can work behind the scene to simplify the creation of HTML documents for large web sites.
  • XML can be used to exchange the information between organizations and systems.
  • XML can be used to download and reload databases.
  • XML can be used to store and organize data, which can customize your data management needs.
  • XML can easily be merged with style sheets to create almost any output you want.
  • Virtually any type of data can be expressed as an XML document.

What is Markup?

XML is a markup language that defines a set of rules for encoding documents in a format that is both human and machine readable.

"Markup" refers to information added to a document that increases its meaning in certain ways as it identifies parts and how they relate to each other.

Is XML a Programming Language?

A programming language consists of grammar rules and its own vocabulary which is used to create computer programs. These programs instruct the computer to perform specific tasks.

XML is not a programming language because it does not perform any calculations or algorithms. It is usually stored in a simple text file and it is processed by special software that can interpret XML.