Types of Waves
Transverse: This wave includes particles that move up and down perpendicular to motion. These waves experience Crests and Trough periodically. A Crest is when the wave reaches its highest point away from equilibrium, the natural position if the wave was to be stretched out completely. A trough is the opposite, the point at which the wave is at its lowest relative to equilibrium. The amplitude of the wave is the distance from the wave to equilibrium at either the trough of the crest.
Longitudinal: A slinky like wave, particles are in constant back and forth motion colliding into each other and creating forward motion. The particles when colliding are in a state of compression with high pressure, after they collide and separate they enter a state of refraction and low pressure.
Surface: Happens when two media are in contact, most commonly water and air. Particles move in a circle and eventually move forward. This type of wave is the waves seen in water on a beach, but on the beach a wave collapses when a particle can finish its cycle because of the sand or winds.