Elastic collision: A collision is known as elastic when kinetic energy is also conserved along with the linear momentum. There is no transformation or loss of kinetic energy in this collision.
Inelastic collision: A collision in which the linear momentum is saved, but a part of kinetic energy change into the other forms is called the inelastic collision. In dissimilar words, the kinetic energy is not conserved. In this, the particles do not gain their size and shape completely after collision. Some fraction of mechanical power is reserved by the colliding bodies in the form of deformation potential energy.