The surface of Earth is complex, but remarkably the result of only two interacting force systems. Heat drives both systems and produces the changes in the Earth that we see during our short lives as well as the changes that only occur over very long time periods we call "geologic time".
The two force systems arise from two sources of heat:
The external heat drives climate, the internal heat drives Plate Tectonics.
Plate tectonics is the unifying theory of the geosciences which nicely explains the distribution and structures in the continents and the structures and features of the ocean basins. It is central to the study of Earth, and Earth is the only planet that we know that posses active plate tectonics.