Difference between sound waves and light waves :
Sound waves :
Longitudinal by nature.
Require material medium to travel.
Cannot travel through vacuum.
Speed is small in air
Produced by vibrating particles of a medium.
Audible sound is of low frequency and high wavelength.
Transverse by nature.
Require no medium to travel.
Can travel through vacuum.
Speed is very high
Produced by vibrating charged particles only.
Visible light is of high frequency and small wavelength.