Reptiles are born in eggs on land and they have lungs. All reptiles breathe using their lungs. Reptiles store their oxygen in their lungs and use it when they are in water or playing dead.
Humans breathe exclusively through their lungs. They take short breaths and use up the oxygen and make it into carbon dioxide in seconds.
Reptiles and Humans have small tiny vessels called alveoli that are used for the exchange of gas in the lungs.