From AT&T Support Wiki
Users who modify Objects via the platform browser user interface (UI) or the Developer Suite tools and APIs will see the [Checkout]/[Commit] buttons, as described in Versioning.
However, users with Administer Versioning permission have an additional option, called [Force Commit]. This button appears to these users when a platform element has been checked out.
It provides the ability to Commit the element by force (that is, without the knowledge or consent of the user who has checked out the element). Because users with Administer Versioning permission are often acting as the System Administrator, it is necessary that they have the ability to commit changes to the code, regardless if the person initiating the change is available to complete the Commit action.