English: A schematic showing the basic types of doors. Note that many variations (subtypes) exist aswell. Note that the wheels in the up-and-over (or overhead) door are actually placed entirely within the rail, but for the sake of clarity of operation, they are placed half in/half out of the rail. Note that the small spacing is thus normally also not present. For a schematic showing the placement of locks depending on door type, see http://commons.wikimedia.org/wiki/File:Placement_of_locks_depending_on_door_type.png