Linnean classification is the traditional classification system of all living things. This system classifies plants and animals by body structure and a descending order of categories. These categories are kingdom, phylum, class, order, family, genus and species.
Carolus Linnaeus, a Swedish scientist, developed this system in the 18th century. Scientists have debated whether this classification system remains relevant in the 21st century, according to Dictionary.com. One possible new system groups together all organisms of a single ancestor and relies on the principles of evolution. Another possible classification system relies on the genetic makeup of DNA or RNA sequences of each living organism.