What kind of animals are frogs?

Amphibians are small vertebrates that need water, or a moist environment, to survive. The species in this group include frogs, toads, salamanders, and newts. All can breathe and absorb water through their very thin skin. Amphibians also have special skin glands that produce useful proteins. Some transport water, oxygen, and carbon dioxide either into or out of the animal.

Source: National Geographic