.gz

File archive compressed using the standard Gnu Gzip compression algorithm; installed with most Unix operating systems; recognized by most file decompression utilities for Mac, Windows, and Unix.

Important: Files that that end in "tar.gz" are known as a "tarballs;" they are commonly found on Unix systems and are .TAR files compressed with Gzip compression; these files must first be decompressed, then expanded using a TAR utility.