When exposed to sunlight, thin films of oil on water often exhibit brilliant colours due to the phenomenon of

When a thin film of oil spreads over the surface of water and it is seen in broad day light, brilliant colours are seen. There, colours arise due to interference of sun-light reflected from the upper and lower surfaces of the film.

While bending of light rays at curvatures of obstacles is called diffraction. Dispersion is splitting of white light and polarisation is the restriction of the vibrations in a transverse wave.