What distinguishes a longitudinal wave from a transverse wave?
Waves are forned by oscillations of the particles in the case of mechanical waves which propagate in material medium and by oscillations of elelctric and magnetic intensity vectors in the case of non-mechanical waves like electromagnetic waves which do not need any material medium for their propagation. When these oscillations are perpendicular to the path of propagation of the waves, they are called transverse waves and when these oscillations are in the direction of propagation of the waves, then they are called longitudinal waves.
