Cannabis, also known as marijuana, weed, sativa, and indica (as well as other names) is a psychoactive drug from the "Cannabis" plant used for medical or recreational purposes. (in legalized states). The main psychoactive part of cannabis is tetrahydrocannabinol (THC), one of the 483 known compounds in the plant, including at least 65 other cannabinoids, which are chemicals only found in Cannabis. Cannabis can be used by smoking, vaporizing, within food, or as an extract.