Wide variety of styles
Lighting fixtures come in a wide variety of styles for various functions. The most important function is as a holder for the light source; to provide directed light and to avoid visual glare. Some are very plain and functional, while others are pieces of art in themselves.
Replaceable light sources
An important property of light fixtures is the luminous efficacy or wall-plug efficiency; meaning the amount of usable light emanating from the fixture per used energy; usually measured in lumen per watt. A fixture using replaceable light sources can also have its efficiency quoted as the percentage of light passed from the “bulb” to the surroundings.
Types of Lighting Fixtures
Indoor lighting is intended for general illumination of an area. This could be a basic lamp on a table or floor, or a fixture on the ceiling.
Lighting for a parking lot may be as low as 10-20 lux (1-2 footcandles) since pedestrians and motorists; already used to the dark; will need little light for crossing the area.