Cannabidiol, or CBD, is a compound extracted from cannabis and hemp plants. Isolated from a hemp plant, CBD was first found in 1940. Later this study got extended, and THC was discovered. After that, researchers recognized a system of receptors called the endocannabinoid system that reacts to CBD and THC.Cannabigerol, or CBG, is a cannabinoid discovered in 1964. It is derived from the Cannabis plant, just like CBD and THC. The only difference is that the CBG comprises just 1% of the average cannabis strain, unlike THC and CBD, which are relatively rich in cannabis.