file format

manner in which the data is stored in a file

A file format is a particular way to encode information for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for different kinds of information. Within any format type, e.g., word processor documents, there will typically be several different formats. Sometimes these formats compete with each other.
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RFC 2048 btoa IFF Animated GIF server-parsed HTML MIME type Symbolic Link base 64 

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