The 'R' in R20 stands for 'reflector.' This type of bulb traditionally included a built-in reflector coating to direct the light. The '20' refers to the diameter of the bulb in 1/8-inch. R20 bulbs offer a diameter of 20/8-inch or 2 ½ inches. They offer an LED energy efficient alternative to traditional, equivalent R20 bulbs, like a CFL, halogen, or incandescent bulb.
R bulbs often see use in recessed or can light fixtures and track lighting. You can often see them in homes, businesses, and retail stores.
BR stands for 'bulged reflector.' Like R bulbs, BR bulbs also included a built-in reflector. However, BR bulbs also featured an additional reflector in the neck of the bulb. This extra reflector creates a slightly bulging shape in the neck of the BR bulb.
Certain BR and R bulbs may act as a flood light bulb if they include a wide beam angle to cover a large space.
The color temperature measures the color of the light emitted from the bulb.
2700K – 3000K – warm, soft white light that works well in family rooms, living rooms, bedrooms, and hospitality locations.
3500K – 4100K – neutral to bright white that works well in kitchens, bathrooms, and commercial applications.
5000K – 6500K – vibrant, cool white light that works well in commercial and industrial applications.