Picture a wave. In the ocean.
You can see it, measure it, its height, the way the sunlight refracts when it passes through.
And it's there, and you can see it, you know what it is.
It's a wave.
And then it crashes in the shore and it's gone.
But the water is still there.
The wave was just a different way for the water to be, for a little while.
The wave returns to the ocean, where it came from and where it's supposed to be.