A light fixture (US English), light fitting (UK English), or luminaire is an electrical device used to create artificial light by use of an electric lamp. All light fixtures have a fixture body and a light socket to hold the lamp and allow for its replacement. Fixtures may also have a switch to control the light. Fixtures require an electrical connection to a power source; permanent lighting may be directly wired, and moveable lamps have a plug. Light fixtures may also have other features, such as reflectors for directing the light, an aperture (with or without a lens), an outer shell or housing for lamp alignment and protection, and an electrical ballast or power supply. A wide variety of special light fixtures are created for use in the automotive lighting industry, aerospace, marine and medicine.
The use of the word "lamp" to describe light fixtures is common slang for an all-in-one luminary unit, usually portable "fixtures" such as a table lamp or desk lamp (in contrast to a true fixture, which is fixed in place with screws or some other semi-permanent attachment). In technical terminology, a lamp is the light source, what is typically called the light bulb. (See Lamp (electrical component).)