The type of waves where the particles in the medium vibrate in the same direction the wave is moving are called longitudinal waves.

Here's why:

* Longitudinal waves: The particles oscillate back and forth *parallel* to the direction the wave travels. Think of a slinky: If you push one end, the compression travels down the slinky, and the coils themselves move back and forth in the same direction as the compression wave.

* Transverse waves: The particles oscillate *perpendicular* to the direction the wave travels. Think of a rope tied to a wall: If you shake the rope up and down, the wave travels horizontally along the rope, but the particles in the rope move vertically.

Examples of longitudinal waves:

* Sound waves

* Seismic P-waves (the first to arrive in an earthquake)

* Compression waves in a spring

* Sound waves in water

Let me know if you'd like to explore any of these wave types in more detail!