PAR lamps or parabolic aluminized reflector lights are electric lamps that illuminate a limited area. They are often mounted in can-shaped fixtures to form a PARCAN which can be used to generate colours by fitting it with coloured sheets (i.e, gels), widely used for concerts, theatres and touring productions.
PAR lamps can achieve a wide range of beam widths, from narrow spot to wide flood. With this versatility, one PAR Can is able to produce a wide range of beams simply by changing the lamp.
They are differentiated according to their diameter, which is measured in eighths of an inch. Therefore, a PAR 64 lamp is two inches in diameter (64/8 = 8 inch or 203mm).