CVS stands for Concurrent Versions System, and is a tool which manages the revision history of a software project. It may be used for single-user projects, and also provides the capability for a group of developers to work on a software project at the same time, allowing them to download the latest version of the source code and incorporate their own changes into the source base.
CVS is a very complex program with a very large manual1, but anyone curious and dedicated enough to read through the information in this document and spend a couple of days absorbing the concepts behind CVS should have very little trouble, and will find that managing projects with CVS, both single-user and group, is much smoother and more convenient than trying to do so without it.
CVS can control more than just source code files for a software project. You can use CVS to maintain any set of text-based files which may be prone to frequent revision, such as web pages, CGI scripts, configuration files, and documentation files (such as this one). Aside from the sections on multiuser access, all of the information herein pertains to both single- and multiuser projects.