There are several cannabinoids found in cannabis, including CBD, also called cannabidiol oil.Marijuana and hemp both belong to the genus cannabis, and the term itself is not necessarily interchangeable with marijuana. CBD oil today is almost entirely made from industrial hemp, which contains negligible amounts of THC, the cannabinoid that causes a high. Agricultural hemp strains are rich in CBD while only having 0.03 percent or less THC, making them ideal for extracting CBD oil.