Explain working of CVS.

CVS acts as a central location where all original project source files are stored. When you open a project file from the CVS server, a copy of the project file is stored on your computer. This helps modify the project file locally without remaining connected to the CVS server.
You can connect to the CVS server and identify the repository you want to access. CVS stores its version-control information in Revision Control System (RCS) files. RCS files are standard byte-stream files with an internal format, which is described by keywords stored in the file itself. You can store RCS files in a directory tree structure called the repository. Files in the repository are stored in a format used by RCS commands.
To work with a repository, you need to checkout files from a specific module into a separate local working directory. To find the specific file, you need to specify the path to the CVS repository.
CVS copies the most revision of each file from the specified module to your local working directory. CVS copies the file unless you explicitly specify a particular revision using revision numbers or tags. You can also specify a particular branch or a section of files to work in CVS.
CVS enables you to work on the client computer without using the server resources. When revisions are final, you can commit files to the repository.
End users working on same projects can checkout files simultaneously. When there are multiple end users working on the same set of files in a project, you can synchronize the files using the update command. This command enables you to include revisions made by other end users into your local working copy.
Adding a tag can freeze a bunch of committed files. Tags are useful because they provide identities to a group of files. You can also use a tag for an entire branch.
You can delete files and the checked out local working directories. If you want to stop using your working copy, invoke the release command. You can also move, rename, or delete entire repositories in CVS. There are various CVS commands that enable you to perform all these tasks.