You can think of the Earth as being made of concentric spheres of matter in different physical states. Hydrosphere - water on Earth, including oceans, lakes and rivers, glaciers, etc. You can think of hydrosphere as lying on top of solid foundation, the lithosphere. Atmosphere - gaseous layer around the Earth. Most of atmosphere is between the surface and 30 km above it.
Atmosphere is the outermost Earth sphere enclosing the other ones.
Biosphere - all living organisms and their habitat. Lifeforms utilize gases from the atmosphere, water from the hydrosphere, nutrients from the lithosphere. In other words, biosphere is dependent on other three realms. Figure on the left shows conceptually the interaction of the four Earth spheres. It is clear that the four realms are not independent, but rather intrinsically interconnected.