For systematic study of any living organism, it is primarily necessary to know where it stands in the living world.
Is it a simple primitive organism, autotrophic or a complex, highly developed and heterotrophic organism? What are the characters that identify its position at a particular level in the living world? This is called classification. Hence, classification denotes arrangement of living beings in specific groups on the basis of their origin, evolution, morphology, anatomy and cytology.
Through this method, the exact position of an organism in this living world can be known accurately. Over the years, various systems of classification-have been developed.