Hydrosphere

• The hydrosphere contains all the solid, liquid and gaseous water of the planet.

• About 97% of the earth’s water is salty and only a small portion is non-salty.

Biosphere

• The biosphere of earth includes all living things on planet Earth like animals, plants and microorganisms. 

• There are different ecological communities divided in six main biomes which are desert, aquatic, forest, grassland, tundra and chaparral.

•  It is the biggest one of all four spheres of earth.

Lithosphere

• The lithosphere/ Geosphere can be defined as the outer boundary layer of solid earth and discontinuity within the mantle. 

• It is a crustal system composed of various layers which are core, mantle and outer crust. It is also known as geosphere.

Atmosphere

• The atmosphere is a complex fluid system of gases and suspended particles. 

• This fluid system forms a gaseous envelope around the earth with no defined boundaries. 

• The total volume of atmosphere is made up of gases like nitrogen, argon, oxygen, carbon dioxide and water vapor etc.