What is a rigid body ? Explain the differences between rigid body and solid body.

Explanation

The distance between all pairs of particles of system (body) do not change then this body is known as rigid body.
Rigid body is a special case of system of particles.
A rigid body is an ideal concept while solved body is a real.
Rigid body is a body with a perfectly definite and unchanging shape. A solid body can be deformed while a rigid body cannot. For many particle purposes a solid can be treated as a rigid body.
For example : Wheel, tops, steel beams, molecules and planets, For a body it can be ignore that they warp, bend or vibrate and treat them as rigid.