Plate Tectonics?

What are Plate Tectonics?
It was a theory, that the Earth's crust, was made out of large and small plates, that float on top of the lava underneath. Now, we know it is not just a theory, and it is the truth. That is now called Plate Tectonics. It has been discovered, that when the plates crashed together, that it is what causes earthquakes and mountains to form. When they move apart, they can create valleys. Those two features are called Convergent and Divergent Boundaries, respectively. The plates themselves move very slowly, 1 cm every year caused by convection currents. They are also moving the continents slowly together, so in a few thousand or million years, we might have a Pangaea again, the prehistoric super continent.