Alligators are large reptiles and members of the order Crocodylia. The two existing species of alligators and the many worldwide species of crocodiles are closely related, and people often confuse one with the other.
An alligator is distinguished by its wide, rounded snout and black color. When an alligator rests with its jaws closed, only its upper teeth are visible. Crocodiles, on the other hand, have narrow, pointed snouts, a grey-green color and both upper and lower teeth visible when the animal’s mouth is closed.
Crocodiles and alligators rarely overlap in range, so another way to tell them apart is to know where you are. American alligators, which live across the southern U.S.