The outer layer of the solid earth is called the crust. Think of the earth like an apple: the crust is the thin, outermost layer, while the core is the dense, central part. The crust is made up of solid rock and is the part of the earth that we live on. It is relatively thin compared to the other layers, only about 10-50 kilometers thick depending on where you are on the planet. The crust is also divided into several large pieces, called tectonic plates, which can move around and sometimes collide with each other, causing earthquakes and volcanic activity. Overall, the crust plays a crucial role in supporting life on earth by providing a stable surface for us to live and grow on.