(N/A) rigid body is defined as a body with a perfectly definite and unchanging shape. The distances between all pairs of particles of such a body do not change,regardless of the external forces applied to it. In reality,no body is perfectly rigid; however,for many purposes,objects like steel balls or wooden blocks are treated as rigid bodies.
$A$ solid body is a state of matter characterized by structural rigidity and resistance to a force applied to the surface. Unlike a rigid body,a solid body can undergo deformation (change in shape or size) when subjected to external forces,such as elastic or plastic deformation.