.tar File — Tape Archive

TAR (Tape Archive) is a file archive format that bundles multiple files and directories into a single file while preserving Unix file system metadata including permissions, ownership, timestamps, symbolic links, and directory structures. Created in 1979 for Unix tape backup operations, tar itself performs no compression — it simply concatenates files sequentially with header blocks. Compression is typically applied as a separate step using gzip (.tar.gz/.tgz), bzip2 (.tar.bz2/.tbz2), xz (.tar.xz/.txz), or zstd (.tar.zst), following the Unix philosophy of composable tools. TAR remains the fundamental archive format on Linux and Unix systems, used for software distribution (source tarballs), system backups, container images (Docker layers are tar archives), and file transfer. The format has evolved through several standards: V7, POSIX.1-1988 (ustar), POSIX.1-2001 (pax), and GNU tar extensions. TAR's streaming design allows creation and extraction without seeking, making it suitable for tape drives and piped operations. The GNU tar implementation is the most widely used and supports transparent compression/decompression.