What is a Lumen?

Lighting – It’s all about lumens. But what are lumens, exactly? Lumens indicate the brightness of the light output or light flow. The Lumens definition is a unit of luminous flux in the International System of Units,
that is equal to the amount of light given out through a solid angle by a source of one candle intensity radiating equally in all directions In short… Lumens equal brightness! Wattage does not indicate brightness but measures the light’s consumption of power. Although we do use the wattage as an easy reference to light intensity. What is important when comparing light fixtures and quality is to compare the lumens per watt.