Consider a pond in which water is very still. Suppose a pole is stuck in the pond and is projecting out of the surface of water. When a small stone is dropped into the pond we notice ripples. When the ripples reach the pole, secondary waves are generated. We say that the pole scatters the incident waves. Experimentally, scattering is a process where a particle (or a system) with a certain energy is sent toward another system (target) and the final motion of the particle is studied after it interact with the system. When the kinetic energy is conserved then the scattering is said to be elastic, otherwise inelastic.