The type of waves that move the particles of the medium parallel to the direction in which the wave is traveling are called longitudinal waves.

Here's a breakdown:

* Longitudinal Waves: The particles in the medium oscillate back and forth in the same direction as the wave travels. Think of a slinky being pushed and pulled, creating a compression and rarefaction pattern.

* Transverse Waves: The particles in the medium oscillate perpendicular to the direction of wave travel. Think of a rope being shaken up and down, creating crests and troughs.

Examples of longitudinal waves:

* Sound waves: Sound travels through air, water, or solids as a series of compressions and rarefactions.

* Seismic P-waves: These are the fastest type of seismic waves and are responsible for the initial shaking during an earthquake.

Let me know if you have any more questions about wave types!