Why are frogs,toads and newts called amphibia?

The woed amphibia comes from two Greek words:amphi meaning'of both kind' and bios meaning 'life'. Amphibia are a class of vertebrate(back-boned) animals that can live both in water and on land. They are descended from fishes that lived more than 300 millions years ago. The first amphibia to crawl out of water were heavily built, and slow and clumsy on land, but more active in water. they had long bodies and tails, and some developed into the highly efficient class of reptiles.(questions and answers)