Final answer:
Plate Tectonics is the theory that explains how the Earth's outer crust is divided into several moving plates.
Step-by-step explanation:
The theory that the Earth's outer crust is divided into several plates that move is called Plate Tectonics. According to this theory, the Earth's lithosphere is divided into several large and small plates which float on the semi-fluid asthenosphere. These plates constantly move and interact with each other, leading to geological activities like earthquakes, volcanic eruptions, and the formation of mountain ranges. For example, the Pacific Plate and the North American Plate are two of the major plates that interact along the Pacific Ring of Fire.
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