What are the types of mechanical waves?

Three types of mechanical waves are transverse waves, longitudinal waves and surface waves. Mechanical waves are different from electromagnetic waves in that they can't propagate in a vacuum; they need a physical medium, such as water or air.

Transverse waves are waves in which particles move perpendicular to the direction the wave is traveling. An example of this is a stretched slinky shaken to move up and down.

Longitudinal waves are waves in which particles move parallel to the direction the wave is traveling. A sound wave is an example of a longitudinal wave.

In a surface wave, particles on the surface of a medium move in a circular motion. For example, an ocean wave at the surface.