What is the thin, outermost rocky shell at the surface of the Earth called?

The outermost rocky shell at the surface of the Earth is referred to as the crust. The crust is a solid layer that varies in thickness, being thinner under the oceans (oceanic crust) and thicker under continental landmasses (continental crust). This layer is essential because it forms the ground we walk on and supports ecosystems, and is also where all terrestrial life exists.

The crust is distinct from the layers beneath it, such as the mantle and the core. The mantle lies directly beneath the crust and is composed of semi-solid rock that flows slowly over geological timescales. The core, located beneath the mantle, consists of primarily iron and nickel and is divided into a solid inner core and a liquid outer core. Therefore, the correct identification of the crust as the thin outermost layer is fundamental to understanding Earth's structure.