Final answer:
The concept that is part of the theory of plate tectonics is the movement of tectonic plates.
Step-by-step explanation:
One concept that is part of the theory of plate tectonics is the movement of tectonic plates. Earth's crust and upper mantle are divided into about a dozen tectonic plates that fit together like pieces of a jigsaw puzzle. These plates can move apart, collide, or slide parallel to each other, causing various geological phenomena such as earthquakes, volcanic activity, and the formation of mountains. The movement of tectonic plates is a fundamental aspect of plate tectonics.