A lamp is a replaceable component such as an incanescent light bulb, which is designed to produce light from electricity. These components usually have a base of ceramic, metal, glass or plastic, which makes an electrical connection in the socket of a light fixture. This connection may be made with a screw-thread base, two metal pins, 2 metal caps or a bayonet cap. Re-lamping is the replacement of only the removable lamp in a light fixture.