More Key Words 3
Version - usually used to indicate a software release milestone (e.g. GNOME 2.0). It has nothing to do with CVS.
Tags - a way to mark all files in a repository at a given point in time. This is often used to coordinate software release versions with CVS revisions. You can tell CVS to tag all current copies with "release 2.0- 12/17/2002". Individual files might have revision numbers - file one -1.1, file two - 1,25, file three - 1.86. You could later retrieve all of the files that made up "release 2.0-12/17/2002" and you would get all of the files just like they were when the tag was applied.
Branch - Revisions to earlier revisions that diverge from the main set of revisions.