Geophysics is the physics of the Earth. Encompassing areas such as seismology, plate tectonics, gravitational anomalies, and the Earth's magnetic field (present and past, as captured in rocks), it brings these together to give clues to both the structure and the workings of our planet. This Very Short Introduction describes the internal and external processes that affect the Earth, as well as the methods, using earth-and satellite-based data, used to investigate them. Throughout, William Lowrie emphasizes our need to understand the history of our planet and the processes that govern its continuing evolution.