A parabolic aluminized reflector lamp (also called PARCAN light, PARcan, or simply PAR) is a type of electric lamp that is widely used in commercial, residential, and theatrical setting. The lamps and their fixtures are widely used in theatre, concerts and motion picture production when a substantial amount of flat lighting is required for a scene.  Par Cans were named for the fact that the fixture, the "can," held a Parabolic Aluminum Reflector. 
 
Commonly they are used to generate colours by fitting them with colored sheets called gels.  The cans are arranged into rows of different colours and identical rows placed on different sides of the stage. Due to their affordability, they are ideal for color washes in several different colors. PARS can be used for special effect lighting such as lighting from directly above or from extreme angles as well as general wash lights overhead and above a stage.
 
The PAR 16 pinspot is a bright point-of-light fixture that's plug-and-play. The PAR can uses a standard AC plug and a standard screw-base lamp up to 50W.
 
PAR 38 cans are excellent for smaller scale theater lighting, medium sized venues, DJ lighting systems, and churches.  The PAR 38 uses a 120 watt bulb.
 
The PAR 56 is an ideal unit for display and stage lighting.  Its long barrel design reduces light glare/spill while maintaining a theatrical appearance.  PAR 56 lamps allows up to 30 ft. with spot angles as low as 14° and flood angles as much as 66°.  Uses up to a 500 watt quartz bulb.
 
Gels are also available for in an array of color options.