Benzene is a clear, colorless liquid with a definite distinctive odor, the key constituent of the aromatic hydrocarbons. It was widely used as a solvent until it was determined to be carcinogenic. The older symbols below show it as a six-membered carbon ring with alternating double and single bonds.
The modern symbol implies the modern understanding that the double bonds are delocalized and shared by all the carbons in the ring.
Shipman, Wilson, Todd