Imagine you are on a swing, moving back and forth. If no one touches you, you will keep swinging for a while until you gradually slow down and stop. That's what happens with a damped sine wave.
A sine wave is a type of up-and-down movement that you can see on a graph. It's like a wavy line that goes up and down repeatedly.
But unlike a regular sine wave that keeps going forever, a damped sine wave starts strong but then gradually loses energy or "damps" as time goes by. This means that the up-and-down movement gets smaller and smaller until it stops completely.
Think of a bell that you hit with a stick - when you first hit it, the sound is loud and clear, but then it fades away until it's completely gone. That's a damped sine wave.
So, a damped sine wave is like a swing or a bell that loses energy over time, and it looks like a wavy line that gradually gets smaller and smaller until it stops.