Why do lithospheric plates move?

Lithospheric plates move becaues of the movement of the molten magma inside the earth.

Lithospheric plates move because of the processes of plate tectonics. Tectonic plates are able to move because the Earth 's lithosphere has a higher strength and lower density than the underlying asthenosphere. Lateral density variations in the mantle result in convection. Plate movement is thought to be driven by a combination of the motion of the seafloor away from the spreading ridge (due to variations in topography and density of the crust, which result in differences in gravitational forces.