Question

What allows the tectonic plates in the lithosphere to move?​

Answer 1

Tectonic Plates are able to move because the Earth's lithosphere has greater mechanical strength than the underlying Asthenosphere.

Lateral density variations in the mantle result is n convection; that is the slow creeping motion of Earth's solid mantle.

Answer 2

Hey!

Your answer is that the Lithosphere is more loosely connected to other plates...(more mechanically powerful is another phrase you can use)

The CONVETION CURRENTS (the movement of Magma which applies a force on it) which occur in the semi-solid upper mantle also contribute to the movement of the Techtonic Plate movement!

I HOPE THIS HELPED YOU!