Compare and contrast the interference and diffraction.

(N/A) $(1)$ The pattern formed in both is due to the superposition of waves.
- The interference pattern is obtained by superposing two waves originating from 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 falls as we move to successive maxima away from the center.
$(3)$ For a slit of width $a$,the first-order minimum of the diffraction pattern is obtained at angle $\theta = \frac{\lambda}{a}$. In interference,the first-order maximum for two slits separated by distance $d$ is at $\theta = \frac{\lambda}{d}$.
$(4)$ In both 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.