What is a lumen?

A lumen is best defined as a unit of measurement for the amount of light emitted by a source. This metric is crucial in the field of lighting, as it quantifies the total visible light emitted in all directions by a light source. It allows for the comparison of the brightness of different light sources, assisting professionals in selecting appropriate lighting for various applications, whether residential, commercial, or industrial.

Lumen measurements are particularly valuable because they relate directly to how much light is perceived by the human eye, influencing the effectiveness of lighting in illuminating spaces and enhancing visibility. In contrast, other options, although related to lighting, do not accurately describe what a lumen represents.