1CVS is a version control system, which allows you to keep old versions 2of files (usually source code), keep a log of who, when, and why changes 3occurred, etc., like RCS or SCCS. Unlike the simpler systems, CVS 4does not just operate on one file at a time or one directory at a time, 5but operates on hierarchical collections of directories consisting of 6version controlled files. CVS helps to manage releases and to control 7the concurrent editing of source files among multiple authors. CVS 8allows triggers to enable/log/control various operations and works well 9over a wide area network (see man pages). 10