Bayonet mount in the context of "Light bulb"

An electric light, lamp, or light bulb is an electrical device that produces light from electricity. It is the most common form of artificial lighting. Lamps usually have a base made of ceramic, metal, glass, or plastic that secures them in the socket of a light fixture, which is also commonly referred to as a 'lamp.' The electrical connection to the socket may be made with a screw-thread base, two metal pins, two metal caps or a bayonet mount.

The three main categories of electric lights are incandescent lamps, which produce light by a filament heated white-hot by electric current, gas-discharge lamps, which produce light by means of an electric arc through a gas, such as fluorescent lamps, and LED lamps, which produce light by a flow of electrons across a band gap in a semiconductor.

A lightbulb socket, lightbulb holder, light socket, lamp socket or lamp holder is a device which mechanically supports and provides electrical connections for a compatible electric lamp base. Sockets allow lamps to be safely and conveniently replaced (re-lamping). There are many different standards for lampholders, including early de facto standards and later standards created by various standards bodies. Many of the later standards conform to a general coding system in which a socket type is designated by a letter or abbreviation followed by a number.

The most common type of sockets for mains electricity are Edison screws, used in continental Europe and North America, while bayonet mounts dominate in the Commonwealth countries, except Canada, and in the automotive industry. Fluorescent lamps typically require a two-pin, unthreaded socket.