Ecology is a vast subject as it includes the life habits of over a million different kinds of living organisms and considers all manners of influences and interactions among them.

In fact, so extensive is the scope of ecology that it seems to have no limits at all. Fortunately, the facts of ecology can be distilled into some remarkable basic and simple principles. The logical starting place is the “Ecosystem”.

The term ecosystem comprises of structural and functional units of living organisms and non-living substances interacting to produce an exchange of materials between themselves. With the ecosystem the terms like “environment” and “habitat” come into discussion.

Environment, literally means “to surround” (from the French verb environed) and therefore includes all conditions, circumstances and influences, surrounding, and affecting an organism or group of organisms.


Habitat is derived from the Latin word, habitare (to dwell). Thus it includes all features of environment in a given locality. Ecosystem, apart from including habitats and environments, specifically refers to the dynamic interaction of all parts of environments, focusing particularly on the exchange of materials between the living and non-living components. Some authors make the scope of environment all inclusive and define ecosystem as a ‘viable unit of environment’.