Amphibia is divisible into Apoda (limbless , burrowing amphibians, with cleidoic eggs .Notable examples are Lehthyophis  and  Gymnophiona , Anura(have adult forms lacking tails  and well developed limbs , their skin is devoid of scales and  is moist/ slimy typically.Vertebrae are fewer and typically procoelous.Notable examples are Rana tigrina , Bufo, Hyla and Alytes etc.  )  and Urodela(Smooth skinned ,lizard like, tailed amphibians possesing branchial arches , gill slits  and even external gills in some cases. Notable examples are Amphiuma  , Ambyostoma etc)
Amphibians are ectothermic, tetrapod vertebrates of the class Amphibia. Modern amphibians are all Lissamphibia. They inhabit a wide variety of habitats with most species living within terrestrial, fossorial, arboreal or freshwater aquatic ecosystems. Amphibians typically start out as larva living in water, but some species have developed behavioural adaptations to bypass this. The young generally undergo metamorphosis from larva with gills to an adult air-breathing form with lungs.