You should study it now to understand the way in which geologic processes and earth materials interact to produce a dynamic Earth. Internal processes are driven by heat energy from remnant and radioactive sources. We sense these processes at the surface in the form of earthquakes, volcanic activity and mountain building. External processes are driven by heat energy from the sun and include weathering , mass wasting, erosion and deposition. Agents of erosion and deposition include running water, ground water, glaciers, waves and currents, and wind.
Internal processes build up the Earth's surface, while external processes level the surface.
The Earth's surface is not level, because internal and external processes struggle with one another to produce an ever-evolving geologic framework and landscape. Plate tectonics is the overriding system which controls the evolution of Earth's geologic framework. We will spend considerable time studying this important theory and you should begin your reading on this topic now.