Final answer:
The Earth's lithosphere is divided into about a c. dozen tectonic plates which are powered by convection currents in the mantle.
Step-by-step explanation:
Earth's lithosphere is divided into about a c. dozen tectonic plates that fit together like the pieces of a jigsaw puzzle. These plates interact with each other at their boundaries in several ways: they can pull apart, one plate can slide under another, they can slide alongside each other, or they can collide and jam together.
The movement and interaction of these plates are powered by convection currents within the mantle, which provide the energy required for the motion of the plates at average speeds comparable to the rate at which human hair grows, which is about 4 to 5 centimeters per year.