What are elastic waves? Name two kinds of elastic waves.

(N/A) Elastic waves are mechanical waves that propagate through a material medium due to the elasticity and inertia of the medium's particles.
These waves require a medium to travel and cannot propagate through a vacuum.
The two primary types of elastic waves are:
$1$. Longitudinal waves: Waves in which the particles of the medium oscillate parallel to the direction of wave propagation.
$2$. Transverse waves: Waves in which the particles of the medium oscillate perpendicular to the direction of wave propagation.