The LED stands for light emitting diode and Par stands for Parabolic aluminized reflector – the number indicates the diameter in eighths of an inch so an Led par 20 is 2 ½ inches at it’s widest point.
These lamps are typically one of the smallest available par light bulbs. This size light bulb is found most of the time in ceiling recessed cans/ hi hats where the space is small and concentrated light is needed.
Lighting Facts CRI Consider selecting light sources (light bulbs) that have a high CRI (color rendering index) like clearly explained in the chart above. This metric though possibly changing to CQS shortly (color quality scale) is still extremely helpful in areas where the true color of an object is needed to be known.
CCT CCT (color correlated temperature) is how you pick the actual color of the light being emitted. If you are thinking this a foreign concept you probably already have been changing this in your space if you ever used a dimmer.
Lumens Lumens are a measure of brightness or more technically a unit of luminous flux emitted from a lamp in all directions. The light flux falling on a surface one square foot in area, every part of which is one foot from a point source having a luminous intensity of one candela in all directions.