There is: Inner Core Outer Core Lower Mantle Crust
Using Models
Imagining what the Earth is like can be very hard, scientists use models to help visulise what it is like, the example below is an egg but other things can be used too.
The shell of the egg represents the crust of the Earth, it is strong but quite thin.
The white represents the mantle of the Earth, the thickest layer. The mantle is made of liquid rock that is flexible