What are the essential points of difference between sound and light waves?

Explanation

(i) Sound waves are mechanical waves which are longitudinal in nature. Light waves are electromagnetic waves which are transverse in character.
(ii) Sound waves need a material medium for propagation, whereas ligh waves do not need any medium.
(iii) Velocity of sound waves in air at NTP `~~332m//sec,` whereas velocity of light waves in air `//` vacuum `=3xx10^(8)m//s`.