Earth is composed of both compositional and physical layers. The compositional layers are the crust, mantle, and core. The crust is on the outermost layer and contains the continents and ocean floor. Below is the mantle, made of soft, wax-like rock. The innermost layer is the core, made of iron and nickel. The physical layers are defined by their properties and include the solid lithosphere, soft asthenosphere, softer mesosphere, liquid outer core, and solid inner core.