A source code management system (SCM) is software that provides coordination and services between members of a software development team.

At the most basic level, it provides file management and version control so that team members don’t write over each other’s changes, and only the newest versions of files are identified for use in the workspace.

But that’s only the beginning. SCMs also give developers the ability to work concurrently on files (in branches that may or may not converge), to merge changes with other developers’ changes, to track and audit changes that were requested and made, to track bug-fix status and to perform releases

Collaboration: SCM tools prevent one user from accidentally overwriting the changes of another, allowing many developers to work on the same code without stepping one each other's toes.

History: SCM tools track the complete development history of the software, including the exact changes which have occurred between releases and who made those changes.

Release notes generation: Given the tracking of each change, the SCM can be used to generate notes for their software releases which accurately capture all of the changes included in the new release.

Documentation and test management: SCM tools can be used to manage not just software source code, but also test suites and documentation for their software.Change notifications: To keep interested members of the team informed when changes occur to the source code.

Project developers who are writing source code.

Project testers who need to download the very latest

changes.

Advanced users who want to try out code that is not

yet stable, mature or released

Subversion

Git

Mercurial

Bazaar

CVS

C-VCS

D-VCS

The Concurrent Versions System (CVS), also known as the Concurrent Versioning System, is a client-server free software revision control system in the field of SCM

Repository

Working Copy

pull-modify-update-resolve-push

Log - history

Get a working copy

Make changes

Test the changes

Check for new changes in the

repository

Commit them back to the

repository

Repeat the above steps till we

have something to release

Tag the release

cvs [global options] command [command options]

checkout

update

commit

log

diff

tag

Wanna definitions ????? I am Sorry

Book: Opensource Devlopment with CVS -3E by Moshe Bar &Karl Fogel VCS by examples by eric sink.

Websites: en.wikipedia.org Better explained.com