Yes but be careful, some maybe be very dangerous or sometimes deadly.
Animals have a variety of names, even within species...for example, snakes have a vast variety of different names, even though they are all still reptiles. Theres anphibions and mammals. Humans are mammals, which are animals which give birth to live young, e.g. crocodiles lay eggs, so is NOT a mammal.
the bum is the only thing that is different between fish and amphibians
Not all amphibians do, some salamanders are live-bearers and some frogs lack a larval stage, they leave their egg as a small frog. Most amphibians do have a larval stage with gills, some will never drop the gills (neonetism) and most frogs and some salamanders will develop lungs. Most salamanders dont have lungs and breathe through their skin. There is no specified reason for having gills and lungs at different stages of their life cycle; apparently it is a good strategy. If it wasn't, frogs would be extinct ;)