what is the difference between scattering and diffraction?
Scattering:-
Scattering is the phenomenon by which a beam of light is redirected in many different directions when it interacts with a particle of matter. When sunlight strikes molecules in our atmosphere, the light is redirected in many directions.
The blue light is scattered more than the red light causing the sky to be blue.
Diffraction:-
Diffraction is the slight bending of light around the edge of an object. The amount of bending depends on the relative size of the wavelength of light to the size of the opening. If the opening is much larger than the light's wavelength, the bending will be almost unnoticeable. However, if the two are closer in size or equal, the amount of bending is considerable, and easily seen with the naked eye.
The colors that seen on a CD or DVD is due to the diffraction of light.