Traditionally, amphibians as a class are defined as all tetrapods with a larval stage, while the group that includes the common ancestors of all living amphibians (frogs, salamanders and caecilians) and all their descendants is called Lissamphibia.
tɹɐdˈɪʃənəli, æmfˈɪbiənz æz ɐ klˈæs ɑːɹ dᵻfˈaɪnd æz ˈɔːl tˈɛtɹɐpˌɑːdz wɪð ɐ lˈɑːɹvəl stˈeɪdʒ, wˌaɪl ðə ɡɹˈuːp ðæt ɪŋklˈuːdz ðə kˈɑːmən ˈænsɛstɚz ʌv ˈɔːl lˈɪvɪŋ æmfˈɪbiənz fɹˈɑːɡz, sˈælɐmˌændɚz ænd kiːsˈɪliənz ænd ˈɔːl ðɛɹ dᵻsˈɛndənts ɪz kˈɔːld lˌɪsɐmfˈɪbiə.