Solution:The inner core, the outer core, the mantle and the crust are the four layers of the earth.The crust is the outermost layer of the earth, and the core is the innermost layer of the earth, located at a depth of 2900 km.
The layer of Earth below the crust is called the mantle. It is about 2,900 km thick and makes up 84% of Earth's total volume.
The crust and the uppermost part of the mantle are called the lithosphere.