PAR is an acronym for "parabolic aluminized reflector." PAR lamps, or bulbs, are a type of reflector lamp with a heavy, durable glass lens that make them appropriate for use in outdoor lighting.
PAR lamps are also used for spot-lighting in theater and stage productions. In this capacity, they are sometimes referred to as PAR cans due to the can-like structure that surrounds the light. Reflector lights, such as PAR lamps, are able to focus and disperse light due to the paint on the lamp. PAR lighting is relatively inexpensive and is used both to pinpoint an area or to provide an accent.