1. filename extensionComputer terminology
Wikipedia definition
2. Filename extensionA filename extension is a suffix (separated from the base filename by a dot) to the name of a computer file applied to indicate the encoding of its contents or usage. Examples of filename extensions are,, and . Some file systems limit the length of the extension (such as the FAT file system not allowing more than three characters) while others do not. Unix filesystems accept the separator dot as a legal character.
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