Earth is comprised of four spheres. The four spheres are lithosphere, hydrosphere, atmosphere and biosphere. Many people use the term geosphere to describe lithosphere. That is wrong. Many people also say that every sphere is essentially a geosphere because it is an integral part of the world. Geosphere is essentially a different classification which is the subject of another discussion.
As the names imply, hydrosphere is the part of the world that is water. It includes all oceans, seas, rivers, lakes and groundwater. Atmosphere is of course air and includes all the levels, right from troposphere to exosphere. Biosphere is all living organisms in the world. It includes humans, all animals, fishes, birds, plants and also microorganisms. Lithosphere is the earth’s crust.
What is Lithosphere?
Earth is a rock. There’s solid rock on the surface, there’s molten rock inside the core and mantle. The land and rocks that form the crust of the earth, which is the topmost layer, is referred to as lithosphere. There are some who believe that all lands and rocks of the earth would be lithosphere. But that is incorrect. The rocks in the mantle or the molten core do not fall under lithosphere. The classification for all land and rocks on and inside the planet is geosphere.
Hence, the hills and mountains or the plateaus you see, the topsoil and the vast terrains of cultivable, arid and semi arid lands, the ocean floors or the riverbeds, the crust that holds the groundwater and all rocks found on the surface of the earth or at the crust are a part of lithosphere. The layer known as lithosphere does not include magma or lava.
Lithosphere is effectively the host of life, of course with help from hydrosphere and atmosphere. All of biosphere resides or thrives in lithosphere. It is lithosphere that supports farming or agriculture, forests, mining of various materials that we need and all our cities or modern infrastructure rests on this layer.
Lithosphere is the most stable of all parts of the world but it is not the most predictable. If you consider the fluctuations in the climate which is effectively the atmosphere, the consistent flow and movement of the rivers and the waves in oceans respectively, then you would find lithosphere to be the safest and the most habitable part of the world. But it is a tad unpredictable when you factor in the tectonic movements.