a archive file, usually compressed with "gzip", with the extension "

a compressed collection of software, much like a

a compressed tar file

a name used to refer to a compressed tar archive

A package of files gathered together using the tar utility. Apache distributions are stored in compressed tar archives or using pkzip.

Tar is a Unix command (meaning 'Tape Archive' and originally referring to a backup that could be retrieved from a tape drive) that creates one archive file from several different files. Tar files are not compressed, but they are collected in one large file for convenient downloading or transferring. 'Tarball' is a slang term for the files that are 'stuck' together in a 'ball of tar' by the tar command.