Taxonomy is the practice of classifying and naming biological organisms and groups of biological organisms. Modern taxonomy originated in the eighteenth century with the work of a Swedish botanist, Carolus Linnaeus, who developed an organized hierarchical classification system that could be applied to all biological organisms. This system is still referred to as Linnaean taxonomy. Under the Linnaean system, all organisms are classified hierarchically into a series of groups from most inclusive to least inclusive. Each species belongs successively to a kingdom, a phylum, a class, an order, a family, a genus, and a species. Sometimes additional categories are used, such as subphylum, superorder, superfamily, subfamily, etc.

One important aspect of taxonomy is the description and naming of biological species. Since the time of Linnaeus, species have been named using what is called binomial nomenclature, in which each species has a two-word name that includes a genus name...