Aliphatic and aromatic compounds

In organic chemistry, hydrocarbons can be divided into aromatic compounds which contain aromatic rings, also known as benzene rings, and aliphatic compounds which do not.

Examples:

* Methane is an aliphatic compound, and contains no aromatic rings.
* Benzene is an aromatic compound, as it is an aromatic ring.
* Toluene is an aromatic compound, as it contains an aromatic ring bonded to a methyl group.