CBD Oil, or cannabidiol, is a chemical compound from the cannabinoid family that naturally occurs in the cannabis plant. Under U.S. law, cannabis is the plant itself, and hemp and marijuana are specific parts of the plant. Hemp refers to the sterilized seeds, stems, stalks and roots. Marijuana is in reference to the viable seeds, leaves and flowers.
The two most known chemical compounds in the plant are CBD and THC, and those two have not much in common.