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file format

In a computer, a file format is the layout of a file in terms of how the data within the file is organized. A program that uses the data in a file must be able to recognize and possibly access data within the file. For example, the program that we call a Web browser is able to process and display a file in the HTML file format so that it appears as a Web page, but it cannot display a file in a format designed for Microsoft's Excel program. A particular file format is often indicated as part of a file's name by a file name extension (suffix). Conventionally, the extension is separated by a period from the name and contains three or four letters that identify the format. A program that uses or recognizes a particular file format may or may not care whether the file has the appropriate extension name since it can actually examine the bits in the file to see whether the format (layout) is one it recognizes.

There are as many different file formats as there are different programs to process the files. A few of the more common file formats are:

  • Word documents (.doc)
  • Web text pages (.htm or .html)
  • Web page images (.gif and .jpg)
  • Adobe Postcript files (.ps)
  • Adobe Acrobat files (.pdf)
  • Executable programs (.exe)
  • Multimedia files (.mp3 and others)
This was last updated in September 2005

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I have a web based paint program that saves files with a .rack extension. I can't find any way to print these files or convert to jpg or other printable format. Any help appreciated.


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