One of the main functions of a source control management application is to place files into a project under version control. After it is under version control, team members can check files out, revise them, and check in new revisions. The application preserves historical information about each file revision. And because of its linking capabilities, you can link a file revision to other items that affected the file or a particular revision of it. A number of other operations can be performed on files, such as moving a file or changing its branching behavior. This section specifically addresses the check-in and check-out operations.