Taxonomy is the study of classification of organisms.
It attempts to describe the relationships among species. The most useful taxonomic systems are phylogenetic , reflecting evolutionary relationships among species. The Linnaean system, and most which followed it, were artificial systems. Artificial systems are ways of grouping organisms by similar features, but not in a way that necessarily reflects evolutionary, or phylogenetic, relationships. Artificial systems are useful for identifying organisms, but they may obscure important evolutionary relationships.