Crocodiles and alligators are members of the crocodilian species but belong to different families. Crocodiles are part of the crocodylidae family, whereas alligators are in the alligatoridae family. The most noticeable difference is the jaw shape. Alligators have a wider U-shaped snout, while crocodiles have a longer, more pointed V-shaped nose. Alligators can reach 15 feet long, whereas some species of crocodiles can grow from 17 to 20 feet.