The Earth's mantle is the layer of rock just below the Earth's crust. Just under the crust, it is solid. It is very hot, and the other part of the mantle is soft, kind of like melted candy.
The Earth's mantle is rock-hard but it actually flows around the outer core, moving about as slowly as your fingernails grow. The mantle tends to be 2,900 kilometers thick, and makes up 84% of Earth's total volume.