In biology, binomial nomenclature is the formal system of naming species. The system is called binominal nomenclature (particularly in zoological circles), binary nomenclature (particularly in botanical circles), or the binomial classification system. The essence of it is that each species name is in (modern scientific) Latin and has two parts, so that it is popularly known as the "Latin name" of the species, although this terminology is avoided by biologists and philologists, who prefer the phrase scientific name. Instead of using the seven-category system in naming an organism, Carolus Linnaeus chose to use a two-word naming system. He adopted the binominal nomenclature scheme, using only the genus name and the specific name or epithet which together form the species name. For example, humans belong to genus Homo and their specific name is sapiens. Humans are then as a species classified by Linnaeus as Homo sapiens. Note that the first name, the genus, is capitalized, while the second is not; both are conventionally italicised.
Species is the lowest rank in this system for classifying organisms.