The environment is the fundamental system which supports all life forms on earth. All the regions across the globe have different animals, vegetation and climatic conditions. The environment comes from a French word; ‘environ’ which means around. The environment can be classified in three types i.e. natural, human and human-made environment.

Natural environment comprises activities and interactions among human beings with the natural surroundings. Human-made environment, is a built environment and includes components of the environment which are strongly influenced by the humans.

The natural environment consists of two components i.e. biotic and abiotic. Biotic components refer to livings beings like plants and animals while abiotic components refer to the non-living things. 175 countries celebrate the earth day on 22 April, to create awareness and appreciation of the earth’s natural environment. 

There are four domains of the environment i.e. the lithosphere, the hydrosphere, the atmosphere and the biosphere. 

Lithosphere forms the solid part of the earth and contains landforms like plateaus, mountains, plains and valleys. It is made up of rocks and minerals and is covered by a thin layer of soil.  Lithosphere hence comprises the crust, core and mantle.

Hydrosphere forms the next layer and covers three-fourth of the earth in form of water bodies. The thin layer of air that surrounds the earth is called atmosphere. The atmosphere forms a protective layer and shields the earth from the strong sunrays. Primarily containing gases, the atmosphere sticks to the earth owing to earth’s gravitational force. The atmosphere consists of stratosphere and troposphere.

Biosphere is the last domain of the earth and is made up of all the plants and animals and all non-living things. It can extend up till any part of the earth where life can exist.