Keys, Locks, handles
Key
A key is a device that is used to operate a lock. A typical key is a small piece of metal consisting of two parts: the blade, which slides into the keyway of the lock and distinguishes between different keys, and the bow, which is left protruding so that torque can be applied by the user.
Lock
A lock is a mechanical or electronic fastening device that is released by a physical object.
Door Handle
A door handle is an attached mechanism used to open or close a door.