Earth is made up of several distinct layers, each with different properties. The crust is the thin, rocky outer layer we live on, ranging from about 5 to 70 kilometers thick, and it's broken into large pieces called tectonic plates that slowly shift over time.
Beneath the crust lies the mantle, a thick layer of hot, slowly flowing rock that makes up most of Earth's volume. Movements within the mantle drive the motion of the tectonic plates above, causing earthquakes, volcanoes, and the gradual reshaping of continents over millions of years.
At Earth's center lies the core, split into a liquid outer core and a solid inner core, both made mostly of iron and nickel. The outer core's flowing metal generates Earth's magnetic field, which protects the planet from harmful solar radiation.