Compare and contrast the interference and diffraction.

Explanation

(1) The pattern formed in both is due to the superposition of the waves.
The interference pattern obtained by superposing two waves originating from the two narrow slits. The diffraction pattern is a superposition of a continuous family of waves originating from each point on a single slit.
(2) The interference pattern has a number of equally spaced bright and dark bands. The diffraction pattern has a central bright maximum which is twice as wide as the other maxima. The intensity fall as we go to successive maxima away from the centre, on higher side.
(3) For a slit of width a, the first order minimum of the diffraction pattern is obtained to be at angle `theta.=(lamda)/(a)`. Where a for two thin slits at distance a, interference pattern for first order maximum is obtained at `theta=(lamda)/(a)`.
(4) In interference and diffraction, light energy is redistributed. If it reduces in one region, producing a dark fringe, it increases in another region, producing a bright fringe. There is no gain or loss of energy, which is consistent with the principle of conservation of energy.