A hydrocarbon with a chemistry similar tothat of benzene. Aromatic hydrocarbons areeither benzenoid or nonbenzenoid. Benzenoidaromatic hydrocarbons contain one or morebenzene rings and are by far the more commonand the more important commercially. Nonbenzenoid aromatic hydrocarbons havecarbon rings that are either smaller or largerthan the six-membered benzene ring. Theirimportance arises mainly from a theoreticalinterest in understanding those structural featuresthat impart the property of aromaticity.Benzenoid aromatic hydrocarbons are alsocalled arenes. Benzene itself is the prototypicalarene.