Here's a breakdown:

* Wave: A disturbance that travels through a medium or space, transferring energy without transferring matter.

* Displacement: The distance a point on the wave moves from its equilibrium or rest position.

* Amplitude: The maximum value of this displacement.

Think of it like this:

* A wave on the ocean: The amplitude is the height of the wave crest (highest point) from the sea level (rest position).

* A sound wave: The amplitude determines the loudness of the sound. A larger amplitude means a louder sound.

* An electromagnetic wave: The amplitude relates to the strength of the wave, like the brightness of light or the intensity of radio waves.

In short, amplitude tells you how strong or intense the wave is.