Cannabis refers to the plant Cannabis sativa, which originated in Central Asia, and has been used medicinally for more than 5,000 years. There are thousands of varieties of the cannabis plant, which differ in their compounds. Compounds in the cannabis plant include phytocannabinoids, such as cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC), and more than 120 other phytocannabinoids, in addition to other compounds like terpenes. The proportion of compounds in the cannabis plant determines its pharmacological properties.
Hemp is a cannabis plant variety. According to its legal definition, hemp refers to cannabis plants with low levels of THC (not more than 0.3% in the US and not more than 0.2% THC in Europe). Hemp was one of the earliest plants with industrial applications in the production of textiles.