Mechanical waves do not require a medium to propagate.

Vibration causes wave's motion

Electromagnetic waves require a medium to propagate

Through is the highest point of a wave

A longitudinal wave is a wave in which particles of the medium move in a direction parallel to the direction of the wave motion

Wavelength refers to the distance between any successive identical parts of a wave

The highest point of a wave is called CREST

Waves that are characterized by particle motion being perpendicular to wave motion are called Electromagnetic waves.

Water waves are examples of mechanical waves.