1. Crust: This is the outermost layer, the one we live on. It's thin compared to the other layers, and is divided into oceanic crust (found under the oceans) and continental crust (found under the continents).

2. Mantle: This is the thickest layer, made of hot, dense rock. It's where convection currents occur, driving plate tectonics.

3. Core: The Earth's center, divided into the outer core (liquid iron and nickel) and the inner core (solid iron and nickel).

Let me know if you'd like more information about any of these layers!