1. Atmosphere: The layer of gases surrounding the Earth.
2. Hydrosphere: All the water on Earth, including oceans, lakes, rivers, and groundwater.
3. Crust: The thin, outermost solid layer of the Earth. It's like the Earth's "skin" and is divided into oceanic crust (thinner and denser) and continental crust (thicker and less dense).
4. Mantle: The thickest layer, made of hot, dense rock. It is mostly solid, but behaves like a very viscous fluid over long periods.
5. Outer Core: A liquid layer composed primarily of iron and nickel.
6. Inner Core: A solid ball of mostly iron and nickel at the Earth's center. It's incredibly hot and under immense pressure.
