BR stands for Bulged Reflector. PAR is short for Parabolic Aluminized Reflector.
What does the number after PAR or BR mean? This number is indicative of the diameter of the lamp in terms of 1/8ths of an inch. For example, a PAR38 bulb is (1/8 x 38)” or 4 ¾” across.
BR (for bulged reflector) bulbs are lamps with “wide flood” beam angles, which means that they provide more than a 45 degree angle when lighting an area.
PAR bulbs are lamps with "narrow flood or spot" beam angles, they provide less than a 45 degree angle like 25°， 40° or less.
A PAR-type bulb may produce more of a spotlight effect, whereas a BR-type bulb typically produces broader illumination, so you may want to look at BR30 bulbs unless you have high ceilings or prefer a more focused beam.
Though PAR 30 bulbs offer more options for lighting, both PAR and BR LED lamps are made to easily replace the energy-stealing halogen and incandescent lights. Because of this, both bulbs have the same medium (E26) base for North American sockets.
BR30 flood light bulbs are a classic choice for 4-inch recessed can fixtures, with their 3.75-inch diameters. We carry 9W LED (65W equivalent) dimmable and non-dimmable version reflector bulbs.
PAR38 flood light bulbs are parabolic aluminized reflectors (PAR). They have 4.5-inch diameters, making them ideal in 5-inch recessed can or track light fixtures.