What is the region of Earth between the crust and core called?

The region of Earth located between the crust and the core is known as the mantle. The mantle is a thick layer of semi-solid rock that extends from just beneath the Earth's crust down to the outer core. It is important for several reasons: it plays a critical role in tectonic activity, including the movement of tectonic plates, and it facilitates the transfer of heat from the core to the crust.

In contrast, the crust refers to the thin outer layer of the Earth where we live, and the core is the innermost layer, composed primarily of iron and nickel. The lithosphere, while consisting of the crust and the uppermost part of the mantle, is not defined as the region between the crust and core; it is instead a rigid layer that forms the tectonic plates within the upper mantle. The mantle's properties and behavior are essential in understanding geological processes, such as volcanism and earthquakes, which makes it a significant focus in the study of Earth science.