Here's a breakdown:

* Wave: A disturbance that travels through a medium or space, transferring energy.

* Rest Position: The undisturbed state of the medium before the wave passes through.

* Amplitude: The maximum displacement of a point on the wave from its rest position.

Think of it like this: If you drop a pebble in a pond, the ripples spreading out are waves. The highest point of each ripple is the amplitude.