CVS is stand for Concurrent Version System. CVS is useful when more than one person work on a particular file .it allows the developers to overwrite the each others changes. Version control system keep the track of work and the changes in the files. and allows the developers to change the data of the file. CVS stores all the version of file in a way that only changes will saves differently and rest is save in a single file.
Sometimes bugs often occurs in code but cannot be find out for a long time then CVS help in retrieving the old version of code and allow the developer to check which part of the code caused bug. CVS provide the facility to the developers to work in an individual directory and then merging the work from each directory. CVS is not a build system while it is a way to control different versions of file.
The basic terms used in CVS are described following