Diffraction due to a Single Slit:
(i) It is produced due' to- different parts of same wavefronts.
(ii) Central fringe is twice as wide as other fringes.
(iii) Intensity of fringes decreases as we go to successive maxima away from the centre.
(iv) At an angle $\lambda $/a, first minima is obtained.
Interference Fringe Young's Double Slit
(i) It is produced due to two different wavefronts.
(ii) Fringe width is of same size.
(iii) Fringes have same intensity.
(iv) At an angle $\lambda $/a, maxima is obtained.