Both sound and light are waves. They have wavelengths and amplitudes. Yet each is a completely different type of wave.

For a start, sound waves cannot be transmitted without a vibrating medium. Within a vibrating medium, such as air, both sparse and dense portions of sound are transmitted. On the other hand, a light wave is transmitted in a vacuum-without a medium-going with waves of electric and magnetic fields.

Sound and light feature different wave shapes, too. A sound wave is longitudinal; the directions of propagation and vibration are the same. A light wave is transverse, the propagation direction being orthogonal to the directions of vibrations. Polarization occurs with only transverse waves.