• Create an archive(bundle together a bunch of files or directories into a single file)
    bzip2 filename.txt
  • Extract files from an archive(recover all the files or directories from the tar file)
    tar -xjf file.bz2
    bunzip2 filename.txt.bz2
  • If the fine ends in .xz (The -J is the flag that specifically deals with .xz files.)
    tar -xJf file.pkg.tar.xz