Users have the ability to check out the current version of a file to prevent the file from being changed. When a file is checked out it cannot be overwritten, deleted and no new versions of the file can be uploaded. This is very useful when multiple users are accessing and working on the same document. For example, if User A is altering a file and has checked it out of the Governance Portal, User B can not make any additional changes to the file until User A has checked the file back in to the Governance Portal.
Only the individual who checked a file out or the administrator can check a file back into the Governance Portal.
or:
Right-click the file and click View Properties.
Note: The check out by and checked out date and time are automatically updated.