Plate tectonics suggests that the floats and moves on the

Plate tectonics suggests that the _PLATE_ floats and moves on the _MANTLE_

Explanation:

The tectonic plates are moving because they float and move on the mantle.  The mantle has many layers, but one of them is like like a thick liquid, or like lava, and that is probably what makes tectonic plates move.

The mantle liquid layer supports everything, but is also in motion... so everything resting on it also moves. That explains the movement of the continents, the creation of mountains and so on.