Subversion (SVN) is a concurrent version control system which enables one or
more users to collaborate in developing and maintaining a hierarchy of files
and directories while keeping a history of all changes. Subversion only stores
the differences between versions, instead of every complete file. Subversion
also keeps a log of who, when, and why changes occurred.

As such it basically does the same thing CVS does (Concurrent Versioning
System) but has major enhancements compared to CVS and fixes a lot of the
annoyances that CVS users face.

This package contains the client, if you're looking for the server end
of things you want subversion-server.