There are 4 main types of LEDs that are most commonly used for growing cannabis. Each type of model has its pros and cons, so there isn’t yet a “best” LED type. 

Quantum Board  
The name “Quantum Board LED grow light” originated from Horticulture Lighting Group, though the term is now sometimes used for any LED in this style. They tend to have relatively low wattage diodes which are spread out over a large area on a board. These are becoming more popular lately, and seem to offer particularly good results for the amount of wattage used. 

Spider Style 
The “spider style” LEDs are similar to Quantum Boards in that the individual diodes are spread out and tend to be on the smaller side, but they are set on a panel with “arms” like a spider as opposed to a solid board. One very popular example is the SPYDRx line of LED lights. These typically have an extremely high price, but growers who use them swear they get better results than any other type of LED grow light. 

Traditional Panel  
The standard panel LEDs have small to medium wattage diodes and the lamps tend to be more compact. Most LED grow lights available today are in this style. They are sort of halfway between a Quantum Board and a COB Style light, with a mix of features from both. 

COB Style 
COB style LEDs use huge COB diodes . Instead of having dozens of small diodes, they typically only have a handful of huge COBs, with strong lenses to direct the light down into the plant. These are rapidly gaining in popularity and are known for having deep penetration into the plant canopy.