Reptiles are vertebrates, they have scaly skin that keeps their bodies from drying out, their young do not go through a larva stage like amphibians, but instead look like small versions of the adults when they hatch. Reptiles are ectotherms, so they must bask in the sun or find a warm spot to get warm and become active, and they must find shade or a cool spot to cool off. In cold conditions they become sluggish and don’t move around much, and some enter a state of torpor or hibernation if it will be cold for a long time.
Amphibians are animals that live part of their lives in water and part on land. Amphibians are vertebrates, and are also ectothermic. They cannot regulate their own body heat, so they depend on warmth from sunlight to become warm and active. They also can’t cool down on their own, so if they get too hot, they have to find a burrow or some other shade. In cold weather, they tend to be sluggish and do not move around much.