Editing Lock and key (section)

{{short description|Mechanical or electronic fastening device}}
{{other uses|Lock and Key (disambiguation)}}
[[File:Solex 99 30 padlock with keys (DSCF2659).jpg|thumb|upright=1.35|A typical modern [[padlock]] and its keys]]
A '''lock''' is a [[mechanics|mechanical]] or [[Electronics|electronic]] fastening device that is released by a physical object (such as a key, [[Keycard lock|keycard]], [[fingerprint]], [[Radio-frequency identification|RFID]] card, [[security token]] or coin), by supplying secret information (such as a number or letter permutation or [[password]]), by a combination thereof, or it may only be able to be opened from one side, such as a door chain.

A '''key''' is a device that is used to operate a lock (to lock or unlock it). A typical key is a small piece of metal consisting of two parts: the ''[[Bit (key)|bit]]'' or ''blade'', which slides into the [[keyhole|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. In its simplest implementation, a key operates one lock or set of locks that are keyed alike, a lock/key system where each similarly keyed lock requires the same, unique key.

The key serves as a [[security token]] for access to the locked area; locks are meant to only allow persons having the correct key to open it and gain access. In more complex mechanical lock/key systems, two different keys, one of which is known as the master key, serve to open the lock.  Common metals include [[brass]], plated brass, [[nickel silver]], and [[steel]]. The act of opening a lock without a key is called [[lock picking]].