"As with everything in the open source world, version control systems (VCSs) come in several flavors. The grandfather of open source VCSs is CVS, a tool that was the de facto standard in the industry for several years until the likes of Subversion came along and made it almost obsolete.
"All the VCSs are broadly categorized into two categories:
1. Centralized version control systems -- The repository is centrally stored on a server. 2. Distributed version control systems -- Every client has the entire repository stored locally.
"CVS and Subversion are two of the most popular centralized VCSs, while Git, Mercurial, Bazaar and Monotone are their distributed counterparts."