Seals are part of a group known as pinnipeds, which also includes sea lions and walruses. Pinniped means "fin-footed" in Latin, referring to their flippered limbs.

There are about 33 species of seals. They are generally divided into two categories: earless seals (true seals) and eared seals. True seals lack external ear flaps and are less agile on land compared to eared seals.