Aromatic rings are a common group in organic chemistry. They are planar ring systems, where a series of double bonds make the molecule conjugated, which means that the p orbitals used for the π bonds overlap with p orbitals on both sides of each carbon atom. Figure 1 shows benzene, one of the simplest aromatic compounds. Though commonly drawn like this, each carbon in the compound is actually bonded in the exact same way to both of its neighbors.
Figure 1. The structure of benzene, one of the simplest aromatic compounds.