Cannabis (also known as marijuana, weed, pot, grass, herb, and many others) is a preparation of the cannabis plant that produces psychoactive effects when consumed (via smoking, vaporizing, or ingestion). The principal psychoactive constituent of cannabis is tetrahydrocannabinol (THC), which makes up one of 483 known compounds in the plant, including at least 84 other cannabinoids such as cannabidiol (CBD), cannabinol (CBN), tetrahydrocannabivarin (THCV), and cannabigerol (CBG).
The genus cannabis is indigenous to central Asia and the Indian subcontinent. The earliest recorded uses of cannabis date from the 3rd millennium BC. At least three species are recognized: Cannabis sativa, Cannabis indica, and Cannabis ruderalis. In modern times, cannabis is used for recreational or medicinal and religious or spiritual purposes.
Since the early 20th century, cannabis has been subject to legal restrictions with the possession, use, and sale of cannabis preparations containing psychoactive cannabinoids currently illegal in most countries of the world. According to a United Nations report, cannabis is the most used illicit drug in the world. In 2004, the U.N. estimated that global consumption patterns of cannabis indicated that approximately 4% of the adult world population (162 million people) used cannabis annually and that approximately 0.6% (22.5 million) of people used cannabis daily.