In this paper we give a pedagogical explanation of coherence effects in non relativistic scattering
processes. Coherent scattering is important not only because it is a clear manifestation of the wave
character of the interaction in these regimes, but also because it helps in increasing the cross
section and thus the observable effects. We show under which conditions a particle scatters
coherently on a multi-particle system. In a nutshell, in order to have coherent scattering, the
incident particle has not to resolve the internal structure of the composite system. We show that
the above condition is satisfied when the de Broglie length of the incident particle is much larger
than the size of the system.