There are two types of crust:
* Continental crust: Thicker (25-70 km) and less dense, made up of granite and other felsic rocks.
* Oceanic crust: Thinner (5-10 km) and denser, made up of basalt and other mafic rocks.
The crust is the outermost layer of the Earth and is where we live, build our cities, and grow our food. It's incredibly thin compared to the other layers of the Earth, making it a very fragile shell!
