Question

what do you understand by the terms dispersion and spectrum ?

Answer 1

Dispersion is basically the phenomenon of splitting the white light into the seven different colours of light constituting it. The visible white light is made up of seven different colours of different wavelength. When the white light is passed through a prism, all the seven colours get splitted which is called dispersion.

Spectrum is that band of light splitted into the VIBGYOR of colours as a result of dispersion of light.