CBD, or cannabidiol, is one of 113 cannabinoids unique to the hemp plant. CBD is produced by the leaves and flowers of female hemp plants. Hemp is defined as all cannabis plants with less than 0.3% THC by weight. Because hemp has such low THC levels, it is non-psychoactive by definition.
CBD and other cannabinoids are produced by the hemp plant because of their unique aromatic and antioxidant activities, which protect the plant from insects, fungus, bacteria, and changes in the environment.