Angular Dispersion
Angular Dispersion is the angular separation between the colors at the extremities of the visible white light spectrum.
It's given by,
Here 'A' is the angle of the prism, μv and μr are the refractive indices of the medium for violet and red rays respectively.
Chromatic Dispersion
Chromatic Dispersion is the phenomenon of variation of wave propagation velocities in a medium in accordance with their wavelengths. Thus light rays of different colors travel with different speeds in a material medium.