Mechanical waves: A mechanical wave is a wave that is an oscillation of matter, and therefore transfers energy through a medium.
Example: Sound waves.
Electromagnetic wave: Electromagnetic radiation consists of waves of the electromagnetic field, propagating through space, carrying electromagnetic radiant energy.
It includes radio waves, microwaves, infrared, light, ultraviolet, X-rays, and gamma rays. All of these waves form part of the electromagnetic spectrum
Transmission of a wave:
Transmission of the wave is the process of movement of wave points with respect to time.
Mechanical wave required medium for transmission.
Electromagnetic waves can transmit even in a vacuum.