The word taxonomy is derived from the Greek words taxis (= arrangement) and numos (=law). It was first coined by A.P. de Candolle, a Professor of Montpellier University in France, in his Botany treatise in 1813, as a French Word “Taxononomie”, evidently formed on the analogue of astronomie, economie, agronomie and other similar words. The Greek scholars criticised this spelling as according to them, the correct Greek spelling should have been “Taxinomie”. Under these circumstances, the correct word presently in use should be spelt as “Taxinomy” instead of “Taxonomy”. But the present day taxonomists prefer the already established term “Taxonomy” as it is in use now for over 170 years.
Systematics, on the other hand, stems from the Latinised Greek word “Systema” applied to the systems of classification developed by Linnaeus in the 4th edition of his historical book Systema Naturae in 1735. It is sometimes incorrectly used in place of taxonomy. Taxonomy is actually the study of the principles and practices of classification and as such it is only a part of systematics.
The Classification is the ordering of animals into groups (or sets) on the basis of their relationships, that is, of associations by contiguity, similarity or both (Simpson, 1961). Or it is the arrangement of the individuals into groups (taxa) and the groups into a system in which the data about the kinds determine their position in the system and thereafter are reflected by the position (Blackwelder, 1967).
The relationship of taxonomy to systematics is somewhat like that of theoretical physics to the whole field of physics. Taxonomy includes classification and nomenclature, but leans heavily on systematics for its concepts. Systematics includes both taxonomy and evolution. Simpson (1961) explains systematics as that scientific study which deals with kinds and diversity of organisms and any or all relationships among them. Or it is that science which includes both taxonomy and classification, and all the other aspects of dealing with kinds of organisms and the data accumulated about them (Blackwelder, 1967). It is thus concerned with organising biological knowledge; taxonomy, with constructing the frame-work for the organisation; and classification is a hierarchy of names of taxa representing the components of a group of plants or animals, with ( included or referred to) characters to diagnose and differentiate the taxa or it is nothing but a list of taxa names indented to indicate category levels. Christoffersen (1995) defined systematics as the theory, principles and practice of identifying (discovering) systems, i.e., of ordering the diversity of organisms (parts) into more general systems of taxa (wholes) according to the most general casual processes.
In simple terms, actually there are two parts of systematics. The first part, taxonomy, is concerned with describing and naming the many kinds of organisms that exist today, those that have been extinct for many, even millions of years and also those that are becoming extinct. The second part of systematics, evolution, is concerned with understanding just how all these kinds of animals arose in the first place and what processes are at work today to maintain or change them.