# Why is benzene aromatic?

Because it has $6$ $\pi$ electrons constrained, and delocalized around a ring.
Benzene satisfies the Huckel criterion, i.e. ; it has $4 n + 2 = 6$ $\pi$ electrons delocalized around a planar ring. This confers special stability, and special reactivity. While benzene is an aromatic carbocycle, heterocyclic aromatics exist, e.g. pyrrole, ${C}_{4} {H}_{4} N H$, furan, ${C}_{4} {H}_{4} O$, etc, in which the lone pairs on the heteroatom are delocalized.