Salamanders are part of a different group of amphibians. The group they belong to is called Caudata. Not all animals in this group are called salamanders, there are also newts, sirens, olms, etc but they are sometimes just lumped into being called salamanders.
The Appalachian Mountains of the United States is the salamander capitol of the world. A third of all salamanders are found in the United States.
Caudata is broken down into 3 groups of living organisms, Cryptobranchoidea – primitive salamanders, Salamandroidea – advanced salamanders, and Sirenidae – Sirens.
There are 10 living families in Caudata and over 700 species.
Cryptobranchidae – Giant Salamanders
Hynobiidae – Asiatic Salamanders
Ambystomatidae– Mole Salamanders
Amphiumidae – Amphiumas
Dicamptodontidae – Pacific Giant Salamander
Plethodontidae – Lungless Salamanders
Proteidae – Mud puppies and Olms
Rhyacotritonidae – Torrent Salamanders
Salamandridae – True Salamanders and Newts
Sirenidae – Sirens