Final answer:
Plate tectonics is the theory that explains how the Earth's outermost layer (tectonic plates) move and change shape.
Step-by-step explanation:
Plate Tectonics is the theory that explains how large pieces of the Earth's outermost layer, called tectonic plates, move and change shapes. These plates rest on a layer of rock and they interact with each other at their boundaries. The movement and interactions of these plates result in various geologic phenomena such as earthquakes, volcanoes, and the formation of mountain ranges.
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