Cannabis, also known as marijuana among other names, is a psychoactive drug from the Cannabis plant used primarily for medical and recreational purposes. Tetrahydrocannabinol (THC) is the main psychoactive component of cannabis, which is one of the 483 known compounds in the plant, including at least 65 other cannabinoids, including cannabidiol (CBD). Cannabis can be used by smoking, vaporizing, within food, or as an extract.