Classification refers to the process of organizing organisms into groups based on their similarities and dissimilarities in order to demonstrate their relationship.
Different systems of classification:
Two Kingdom System of Classification: It is proposed by Carolus Linnaeus in 1758. On the basis of habitat, cell structure, nature of the cell wall, mode of nutrition, methods of reproduction etc, the creatures were split into two kingdoms in this categorization system: the plant kingdom and the animal kingdom.
Three Kingdom System of Classification: It is proposed by Ernst Haeckel. Along with the plant and animal kingdoms, the kingdom Protista was included in this.
Four Kingdom System of Classification: It is proposed by Copeland. Kingdom Monera was also included in this categorization scheme.
Five Kingdom System of Classification: It is proposed by Robert Whittaker. Kingdom Fungi was also included in this categorization scheme. It shows the phylogenetic relationship between diverse groups with regard to levels of organization and mode of nutrition.