A
lamp is a replaceable component that produces
light from
electricity. Compact lamps are commonly called
light bulbs; for example, the
incandescent light bulb. Lamps usually have a base made of ceramic, metal, glass or plastic, which secures the lamp in the socket of a
light fixture. The electrical connection to the socket may be made with a screw-thread base, two metal pins, two metal caps or a bayonet cap.