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XML Guide

XML - Extensible Markup Language (EXtensible Markup Language)

XML is a cross-platform tool for communicating information and independent software and hardware.

XML document instance

<?xml version="1.0"?>
< note >
< to > Tove </ to >
< from > Jani </ from >
< heading > Reminder </ heading >
< body > Don't forget me this weekend! </ body >
</ note >

What is XML?

  • XML means Extensible Markup Language (EXtensible Markup Language)
  • XML is a markup language, very similar to HTML
  • XML was designed to describe data
  • XML tags are not predefined. You need to define your own labels.
  • Using XML document type declaration (DTD) or XML Schema to describe the data.
  • XML with a DTD or XML Schema is designed to be self-descriptive.
  • XML is a W3C standard

XML does not do anything

ML is to do nothing. XML structure to create, store and carry information.

Examples of the above XML document is written in XML to Tove from Jani a piece of paper. Note that the title and the message body. It also has information about where came from. However, this XML document does not do anything. Just pure information wrapped in XML tags. Someone must write a piece of software to send, receive or display it:


To: Tove
From: Jani

Do not forget me this weekend!

XML tags are not predefined

XML tags are not predefined, you must "invent" your own tags.

HTML tags used to mark documents are predefined HTML file authors can only be used in the HTML standard (such as <P>, <H1>, etc.) defined label.

XML allows the author to define his / her own label and his / her own document structure.

In the example above (like <to> and <from>) tag is not defined in any XML standard. These tags are XML document author "invented".

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How to learn XML?

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