Is crocodile a reptile or an amphibian?

Crocodiles are reptiles. While they live both on land and in water, that in itself doesn't make them an amphibian. It lacks other amphibian characteristics, like a moist, glandular skin that lacks scales and feathers. 

While a crocodile, like a reptile, has dry, scaly skin that helps prevent water loss and provides them protection. They lay their eggs on ground.