Elasticity is ability of a deformed material body to return to its original shape and size when removing the forces causing the deformation. A body with this ability is said to behave or respond elastically. To a greater or lesser extent, most solid materials exhibit elastic behavior, but there is a limit to the magnitude of the force, and the accompanying deformation, within which elastic recovery is possible.
Inelasticity is the opposite of elasticity, i.e. materials that do not return to their original shape and size after deformation.