Here's a breakdown:

* Crest: The highest point of a wave.

* Trough: The lowest point of a wave.

The particles in a transverse wave move perpendicular to the direction the wave travels. Imagine shaking a rope up and down. The rope itself moves up and down (perpendicular to the direction the wave travels along the rope), creating crests and troughs.

Here are some examples of transverse waves:

* Light waves: Electromagnetic waves that travel at the speed of light.

* Water waves: The up-and-down motion of water creates waves that move across the surface.

* Seismic S-waves: These waves travel through the Earth's crust during earthquakes.

Let me know if you'd like to know more about transverse waves!