Difference between the diffraction and interfernce pattern of single slit

Note that the intensity of the bright fringes in an interference is equally bright, equally spaced. In a diffraction pattern, the central maximum has the greatest brightness, with each successive bright fringe getting narrower and dimmer.

 

     

 

Given below is a sketch of an intensity pattern that shows the combined effects of both diffraction and interference when light passes through multiple slits.

 

 

Notice that the diffraction pattern forms "an envelope" around the interference pattern that defines the intensity of the interference fringes. Also notice that since the interference fringes REMAIN equally spaced, some of the bright fringes are "squelched" by diffraction minima.