SCATTERING OF LIGHT= Scattering (or Rayleigh scattering) occurs when certain particles are more effective at scattering a particular wavelength of light. ... This means that almost all of the light which enters clouds will be scattered. Because all wavelengths are scattered, clouds appear to be white.

DISPERSION OF LIGHT= Dispersion is the property by which light is spread out according to its color as it passes through an object. For example, when you shine a white light into a , all of the different colors of light are bent different amounts, so they spread out and make a rainbow.