The Quartermaster is a position that is found both on and off starships, and has varying degrees of authority. He is responsible for supplying all materials to his given area, and must maintain and police the distribution throughout.
Many ships and stations have their own quartermaster, who will maintain supplies on board that ship or station. However, entire sectors may have a single quartermaster, as was the case with the Bajor sector during the Dominion War. In these cases, a single officer is typically responsible for coordinating the efforts of all ship supplies, much as a fleet's admiral will coordinate the command structure.