Here's a breakdown:
* Crust: The outermost layer of Earth, composed of relatively light, solid rock. It's about 30-50 km thick under continents (continental crust) and 5-10 km thick under oceans (oceanic crust).
* Mantle: The thickest layer of Earth, extending from the crust to about 2900 km deep. It's mostly solid but behaves like a very viscous fluid over long periods.
* Outer Core: A liquid layer of iron and nickel, extending from 2900 km to 5150 km deep.
* Inner Core: A solid ball of iron and nickel at Earth's center, extending from 5150 km to 6371 km deep.
While the crust is the thinnest layer, it's the one we interact with directly and is crucial for life on Earth.
