COB (chip on board) LEDs are a type of LED that uses multiple small LED chips mounted on a single substrate. This creates a high-density and powerful light source that can penetrate deep into the canopy. COB LEDs are known for their high output and quality, but they also generate more heat and consume more electricity than other types of LEDs. Quantum boards LED grow lights are a type of LED light that uses multiple large LED chips mounted on a thin, flat board. This creates a low-density and diffuse light source that can cover a large area evenly. Quantum board LEDs are known for their efficiency and versatility, but they also have lower output and quality than COB LEDs.