-A system which tracks versions, usually of SourceCode, but potentially any digital content. It allows multiple people to work on a project, automatically coordinating everyone's changes with everyone else's — much like the wiki. Having a project versioned makes it possible to roll back erroneous changes, find out when bugs or errors were introduced and by whom, work multiple branches of the same thing simultaneously without conflicts, and many things more. Different VersionControlSystem~s have different sets of features in terms of multiple file handling, MetaData versioning, distributed storage, security goals, etc.