The difference between an alligator (left) and a crocodile (right)
As you can see in the photo, the biggest difference in their appearance lies in their jaws: the crocodile's mouth is V-shaped, while the alligator's is more U-shaped. Their skin color also differs—crocodiles are greenish, while alligators are black or dark green.
And last but not least, crocodiles are considered to be significantly more aggressive and prone to attack than alligators.