PAR stands for Parabolic Aluminized Reflector; this type of LED bulb is used for a focused and narrow beam of light. They do not exceed the angle of 45 degrees in most cases. MR stands for Multi-faceted Reflector. They have the narrowest beam of light and are mostly used as a spotlight. BR stands for Bulged Reflectors. These have the widest beam of light and are mostly used as floodlights. The angle of the beam often exceeds 100 degrees.