1. A file packaging tool included with UNIX/Linux for the purpose of assembling a collection of files into one combined file for easier archiving. It was originally designed for tape backup, but today can be used with other storage media. When run by itself, it produces files with a .tar extension. When combined with Gzip, for data compression, the resulting file extensions may be .tgz, .tar.gz or .tar.Z. From I-gloss