Materials that are said to undergo change in their shape and can be compressed are said to be ductile and malleable.
The changes that are brought about are not permanent in these.
When a force or stress is applied to bring about a change in the shape or deformation in any material such that it is permanent is known as the plasticity of the material.
This plasticity is dependent on the ductility and malleability of the material. These deformations are irreversible and can not be altered to previous state.
The stress applied is of moderate magnitude and lies between the temporary deformation and elastic nature.
It is also necessary that the change induced does not break or rupture the material.
Plasticity in a material is brought about by exposing it to high temperature and pressure, in general.