What does the port xz do in Macports?

I'm new to macports. I want to install a certain port called gimp-gap, but first I have to install 'xz'. But what does this port actually do?

xz is a compression/decompression tool like zip, bzip2, gzip, and compress.

$ port info xz
xz @5.2.1 (archivers)
Variants:             universal

Description:          XZ utils consist of a few relatively separate submodules:
                      * LZMA/XZ encoder/decoder command line tool similar to
                      gzip/bzip2 * Scripts to ease grepping, diffing and viewing
                      (lz*grep, lzdiff/lzcmp, lzmore/lzless)
Homepage:             http://tukaani.org/xz/

Library Dependencies: libiconv, gettext
Conflicts with:       xz-devel
Platforms:            darwin
License:              public-domain GPL-2+
Maintainers:          [email protected], [email protected]
$