PowerAda Versioned Object Bases (VOBs) and Views
(Much of this text is drawn from the ClearCase Reference Manual entry for VOB.)
A Versioned Object Base (VOB) is a data repository for a directory tree. The VOB is activated on a host by mounting it as a Multi-Version File System. Users must define a particular view through which the VOB is accessed. The view is associated with a Config Spec which defines how the view selects versions from the VOB. For example, one view may consist of 'the latest version of all files prior to 11:30 PM Friday'. Such a view would correspond, in a repository-based CM system, to a directory tree extracted at that time.
Another useful definition of a view is 'the latest version of all files, and the checked-out version of all files I have reserved'.