Editing Concurrent Versions System (section)

== Design ==

CVS operates as a [[front end and back end|front end]] to [[Revision Control System]] (RCS), an older version control system that manages individual files but not whole projects. It expands upon RCS by adding support for repository-level change tracking, and a client-server model.<ref name="Stopak" /> Files are tracked using the same history format as in RCS, with a [[hidden directory]] containing a corresponding history file for each file in the repository.

CVS uses [[delta compression]] for efficient storage of different versions of the same file. This works well with large text files with few changes from one version to the next. This is usually the case for source code files. On the other hand, when CVS is told to store a file as binary, it will keep each individual version on the server. This is typically used for non-text files such as executable images where it is difficult to create compact deltas between versions.

CVS excludes [[symbolic link]]s because when they are stored in a version control system they can pose a security risk. For instance, a symbolic link to a sensitive file can be stored in the repository, making the sensitive file accessible even when it is not checked in. In place of symbolic links, scripts that require certain privileges and conscious intervention to execute may be checked into CVS.{{citation needed|reason=cleanup of text|date=July 2017}}