The outermost layer of the Earth is called the crust.
Explanation:
Crust:
This is the solid, outermost layer of the Earth, made up of solid rock.
Mantle:
The layer directly below the crust, which is much thicker and composed of molten rock.
Outer core:
A liquid layer surrounding the inner core, made primarily of iron and nickel.
Inner core:
The solid center of the Earth, also made of iron and nickel, but under immense pressure.