Cannabinoids is a broad term to describe the pharmacologically active naturally occurring substances found within the cannabis (marijuana) plant, with the two most studied cannabinoids being Δ9-tetrahydocannabinol (Δ9-THC) and cannabidiol (CBD).  Studies with these two compounds led to breakthrough discoveries that the body made its own endogenous cannabinoids (endocannabinoids).  Two of the most studied endocannabinoids include anandamide (AEA) and 2-arachadonoyl-glycerol (2-AG), which act as neurotransmitters by binding to CB1 and CB2 receptors.  Plant derived cannabinoids, such as Δ9-THC and CBD, act as direct agonists at these receptors.