Lock and key

A lock is a <a href="/facts/Mechanics/A3yHLQA5">mechanical</a> or <a href="/facts/Electronics/E4JhgISq">electronic</a> fastening device that is released by a physical object (such as a key, <a href="/facts/Keycard_lock/2SNlkH9F">keycard</a>, <a href="/facts/Fingerprint/5WLcd20T">fingerprint</a>, <a href="/facts/Radio-frequency_identification/4CnmIV2b">RFID</a> card, <a href="/facts/Security_token/0V55fErB">security token</a> or coin), by supplying secret information (such as a number or letter permutation or <a href="/facts/Password/WEoul230">password</a>), 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 <a href="/facts/Bit_(key)/YSEDQYd9">bit</a> or blade, which slides into the <a href="/facts/Keyhole/znm9Kpjb">keyway</a> 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 <a href="/facts/Security_token/0V55fErB">security token</a> 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 <a href="/facts/Brass/pe8EHk6x">brass</a>, plated brass, <a href="/facts/Nickel_silver/mXMKcugp">nickel silver</a>, and <a href="/facts/Steel/aN6qWo4H">steel</a>. The act of opening a lock without a key is called <a href="/facts/Lock_picking/0gshkmVA">lock picking</a>.

Lock and key open-in-new

Lock and key