The thin layer of rock on the Earth's surface is called the crust.

There are two types of crust:

* Continental crust: This is the thicker, less dense crust that makes up the continents. It's primarily made of granite and is about 30-70 km thick.

* Oceanic crust: This is the thinner, denser crust that makes up the ocean floor. It's primarily made of basalt and is about 5-10 km thick.

The crust is the outermost layer of the Earth and is constantly being changed by processes like plate tectonics, weathering, and erosion.