Because of the process of energy depletion from the inner part of the Earth, waves that spread outwards from the seismic focus of the earthquake are called seismic waves.
They are mainly divided into:
1. Body waves: Such waves that arise due to the release of energy from the source center of the earthquake and through the inner part of the Earth, move forward in all directions, are called body waves.
2. Surface waves: New waves caused by interaction between body waves and surface matter are called the surface waves.