There are three types of classification of living organism.
Artificial system: It is based on the limited number of characters of living organism and is use for primary identification of living organism.
Example: Plants – Herbs, shrubs and trees
Animals – Aquatic, terrestrial and aerial
Natural system: It is based on the similarities and differences in the large number of characters and employed for plants and animals. Organisms are classified into plant kingdom and animal kingdom.
Plants are immobile and possess autotrophic mode of nutrition. Animals are mobile and possess heterotrophic mode of nutrition. This system of classification is very simple but having some exceptions like algae and fungi are included in plants but both are having different mode of nutrition. An alga is autotrophic and a fungus is heterotrophic by nature.
Phylogenic system: It is based on the evolution of life and shows the genetic relationships of organism. Whittaker’s five kingdom system of classification is based on this type.