What term describes the solid, outer part of the Earth?

The term that describes the solid, outer part of the Earth is the lithosphere. The lithosphere encompasses the crust and the uppermost portion of the mantle, and it is characterized by its rigid and solid structure. This solid outer layer is crucial for many geological processes, such as tectonic activity, as it includes landforms, rocks, and minerals that make up the Earth's surface.

In contrast to the lithosphere, the hydrosphere refers to all the water on Earth, including oceans, rivers, lakes, and glaciers. The biosphere encompasses all living organisms and their interactions with the environments in which they live, while the atmosphere is the layer of gases that surrounds the planet. Each of these spheres contributes to the Earth's system but pertains to different components of the planet.