SVN vs. CVS

Since Subversion is meant to be a replacement for CVS, it supports most of CVS's features (exceptions usually come when a CVS “feature” could more correctly be called a “bug”)
SVN offers a command-line interface that is very familiar that of CVS
Directories, renames, and file meta-data are versioned, unlike CVS
Commits are truly atomic
Revision numbers and log messages are per commit, not per-file as in CVS
A branch is simply a tag that has been committed to (a sort of copy-on-write system, if you will)

Since Subversion is meant to be a replacement for CVS, it supports most of CVS's features (exceptions usually come when a CVS “feature” could more correctly be called a “bug”)