CVS is a version control system, an important component of Source Configuration Management (SCM). Using it, you can record the history of sources files, and documents. It fills a similar role to the free software RCS, PRCS, and Aegis packages.

CVS is a production quality system in wide use around the world, including many free software projects.

While CVS stores individual file history in the same format as RCS, it offers the following significant advantages over RCS:
It can run scripts which you can supply to log CVS operations or enforce site-specific polices.

Client/server CVS enables developers scattered by geography or slow modems to function as a single team. The version history is stored on a single central server and the client machines have a copy of all the files that the developers are working on. Therefore, the network between the client and the server must be up to perform CVS operations (such as checkins or updates) but need not be up to edit or manipulate the current versions of the files. Clients can perform all the same operations which are available locally.

In cases where several developers or teams want to each maintain their own version of the files, because of geography and/or policy, CVS's vendor branches can import a version from another team (even if they don't use CVS), and then CVS can merge the changes from the vendor branch with the latest files if that is what is desired.

Unreserved checkouts, allowing more than one developer to work on the same files at the same time.

CVS provides a flexible modules database that provides a symbolic mapping of names to components of a larger software distribution. It applies names to collections of directories and files. A single command can manipulate the entire collection.