tar(1) xvfz filename.tar.gz
The GNU version of the tar archiving utility
-x, --extract, --get
      extract files from an archive
-v, --verbose
      verbosely list files processed
-f, --file ARCHIVE
      use archive file or device ARCHIVE
-z, --gzip, --gunzip --ungzip
tar [-] A --catenate --concatenate | c --create | d --diff --compare | --delete | r --append | t --list |
    --test-label | u --update | x --extract --get [options] [pathname ...]
source manpages: tar