CBD is short for cannabidiol. CBD and its famous cousin, THC (tetrahydrocannabinol) are part of a family of compounds called cannabinoids. Cannabinoids are simply compounds that are derived from cannabis plants. CBD itself is not psychoactive and there is some evidence to suggest it has therapeutic uses.
CBD does not get the user “high,” since it doesn’t necessarily contain THC. It is valued by consumers for its therapeutic effects.
What is a cannabis plant? It seems basic but it’s worth walking through that cannabis sativa is the Latin name for the plant that produces both marijuana and industrial hemp. Marijuana is a Schedule I drug while industrial hemp is not. From a legal perspective, the only difference between marijuana and hemp is how much THC is in it. Marijuana is the legal term of art for cannabis that has more than 0.3% THC by dry weight. Any less than 0.3% THC and it is hemp. Cannabis is simply the umbrella term for both.
THC is the reason that marijuana is a Schedule I drug. THC is the psychoactive compound in marijuana. Until recently, anything from a marijuana plant was considered subject to DEA enforcement as a Schedule I drug. A hemp plant, however, was exempt from DEA enforcement because Congress specifically wrote the Farm Act to exempt industrial hemp (that is, cannabis sativa with less than 0.3% THC by weight).