Version control : versioning is the making of copies of data

at some meaningful point in order to return to that point at

a later date, if necessary.

In Software feild so many version control tool are there

SCM tool

VSS tool

cvs tool

pvcs tool

Rational clearcase proides tool support versions all types

file and directories in source repositry .

software feild best version tool is clearcase it support

version control,merging,compare version of software

resource,parallel development...

Version control tools help multiple users to make

simultaneous changes to a collection of documents/files,

without clobbering each others' work or resulting in version

confusion