Difference between Interference and Diffraction

Interference and diffraction are closely related and can be hard to sharply distinguish, since both exhibit the wave nature of light, both involve light reaching geometrically shadowed regions, and both produce maxima and minima by interference of waves. Their differences, based on appearance and origin: interference is the superposition of exactly two waves, from two coherent sources, giving equally-spaced fringes of almost equal intensity, with a large number of visible fringes; diffraction is the superposition of secondary wavefronts emitted from many different points of the same single original wavefront, giving unequally-s …