What is the difference between cannabis, hemp, and marijuana?

Technically speaking, both "marijuana" and "hemp" are cannabis. Cannabis is the proper botanical name for the plant, while hemp and marijuana are historically slang terms often used to describe cannabis.

Hemp and marijuana are both derived from the cannabis plant and both contain delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), along with many other constituents, often in varying ratios. Hemp and marijuana are visibly indistinguishable as a plant.

In the 2018 Farm Bill, the federal government officially reformed the definition of marijuana and created distinctions between hemp and marijuana, designating hemp consisting of a THC content at or below 0.3%, and marijuana consisting of a THC content exceeding 0.3%.

The 2018 Farm Bill resulted in the reclassification and removal of hemp from the Schedule I category of the Controlled Substance Act. Therefore, hemp is now federally legal to grow and consume, as long as the THC content remains <0.3%. Marijuana, with a THC content above 0.3%, remains a Schedule I substance and is illegal on a federal level.