Wave Propagation
Wave Propagation is how a wave moves energy from one place to another without carrying matter along.
Think of it this way
Drop a stone into a bowl of water. Ripples spread out in rings from the center. The water itself does not move outward — each part just bobs up and down in place. The energy passes through the water from one ring to the next.
Explaining wave propagation by grade level
When you push one end of a long rope, a bump travels to the other end. Your hand stays still after the push, but the bump keeps going. The rope moves up and down, not forward. The energy moves forward even though the rope does not.