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XML File Format

eXtensible markup language

 XML is a file extension for an Extensible Markup Language (XML) file format used to create common information formats and share both the format and the data on the World Wide Web, intranets, and elsewhere using standard ASCII text.

XML is similar to HTML. Both XML and HTML contain markup symbols to describe the contents of a page or file. HTML, however, describes the content of a Web page (mainly text and graphic images) only in terms of how it is to be displayed and interacted with. For example, the letter "p" placed within markup tags starts a new paragraph.

XML describes the content in terms of what data is being described. For example, the word "phonenum" placed within markup tags could indicate that the data that followed was a phone number. An XML file can be processed purely as data by a program or it can be stored with similar data on another computer or it can be displayed, like an HTML file. For example, depending on how the application in the receiving computer wanted to handle the phone number, it could be stored, displayed, or dialed.

XML is considered extensible because, unlike HTML, the markup symbols are unlimited and self-defining. XML is a simpler and easier-to-use subset of the Standard Generalized Markup Language (SGML) standard for how to create a document structure. It is expected that HTML and XML will be used together in many Web applications. XML markup, for example, may appear within an HTML page.

MIME type: text/xml, application/xml, application/x-xml


Learn more about XML files:

See our HTML, XHTML and XML cheat sheets. provides news, expert advice and other learning resources on XML.

Visit the W3C webpage for more information about XML.

Find answers to your XML questions at IT Knowledge Exchange.

This was last updated in August 2010
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XML is great stuff,
XML is fun
From an IPhone, how does one download to a computer, not only the .jpg images, but also the metainformation about date and location that appears atop each image as viewed from the phone?



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