Light Output (Lumen)
Light Output is an informal term for how much light a fixture produces, and how the fixture emits and distributes that light.
Luminous flux is the term to describe the total output of light from a light source. The unit used for luminous flux is lumen.
Because the lumen rating for a lamp is the total output of light in all directions from that lamp, the higher the rating the “brighter” the lamp will appear. For example, a wax candle generates about 13 lumens; a 60-watt bulb approximately 800, and a 100-watt bulb 1,600 lumens.