Earth's four spheres are: the lithosphere , the atmosphere , the hydrosphere , and the biosphere .
Every thing on Earth can be placed in one of the four major subsystems or spheres.
The Lithosphere refers to the land mass which includes all forms of terrestrial structures and zones.
The Atmosphere refers to the blanket of air that covers the air which is itself divided into subspheres: the troposphere, the stratosphere, the mesosphere, and the thermosphere which contains the ionosphere and the exosphere.
The Hydrosphere refers to all water bodies, liquid and frozen (sometimes called the cryosphere), salt and fresh, surface or underground.
The Biosphere refers to all living creatures that exist.