In computing, the tar file format is a type of archive file format: the *T*ape *AR*chive format. These files are produced by the Unix command tar and were standardized by POSIX.1-1998 and later POSIX.1-2001.
It is used widely to archive and unarchive files, which means to accumulate a large collection of files into a single archive file (packer), while preserving FileSystem information such as user and group permissions, dates, and directory structures.
In the Unix philosophy of "one job, one program", it does not support compression directly. If you then want to compress your archive, you use a separate program that is specialised in compression. tar is most commonly used in tandem with an external compression utility such as gzip or bzip2, since it has no built in data compression facilities. These compression utilities generally only compress a single file, hence the pairing with tar, which can produce a single file from many files.
- .tar , for tar file.
- .tar.gz or .tgz (only when compressed by gzip)
- .tar.bz2 or .tbz (only when compressed by bzip2)