According to SMS Research Team Any animal that can Survive both on Water and Land is called An Amphibian.

Examples of Animals that can Survive both on water and In Land are : Salamanders, Toads and Frogs.
The characteristic of Amphibians is that it Respire Through its Skin. The Newest Species Of Amphibians Are thought With Gills on how to start life in the Water.

The process of Amphibians Learning how to live with Gills is called "Metamorphosis".
The Species Undergoes Changes that are Physical and Help Develop them to Adult Forms.
During the Process of Growth, The Adult Species of Amphibians usually Retain their Gills .

If some amphibians Retain their Gills many of them will develop Little Lungs inside their System during their adult Forms.

According To SMS Research Team, Amphibians Usually develop Caecilian. Caecilian Looks Exactly Like Worms and One of the Major Characteristics and Findings is that it has no Legs or Sign of Legs.
Other Species of Amphibians that develop leg does not Develop Rare order like Caecilian.

According to Ktd Website, Amphibians Originated from a Greek Root which Scientifically Means " Dual Life".

The Greek Word Puts it Reflection based on The Double Life Amphibians poses.
The Double Life are Refered Scientifically Based on Their Existence on Land and in the Water.