In simple terms, Lumens (denoted by lm) are a measure of the total amount of visible light (to the human eye) from a lamp or light source. The higher the lumen rating the “brighter” the lamp will appear.
Lumens vs ANSI LumensWhat are Lumens or ANSI Lumens? - Projector1
What Are Lumens in Lighting - Setick
What are Lumens?
What Are Lumens in LED Lights - Comprehensive Guide
Lumen
KAIYAAN - The Meaning of Lumens What are lumens, anyway?
What are Lumens? – The Mercury Group
What are Lumens and Why You Should Care - Factor Equipment
What's the difference between Lumen and Lux? - LumenBasic