Binomial nomenclature is the system of nomenclature in which each species of animal or plant receives a name of two terms of which the first identifies the genus to which it belongs and the second the species itself. The genus is capitalized and species is in lowercase, both written in italics. Both the terms are in latin grammatical forms, although they can be based on words from other languages. The formal introduction of this system of naming species is credited to Swedish natural scientist Carl Linnaeus, in his work Species Plantarum in 1753. The application of binomial nomenclature is now governed by various internationally agreed codes of rules, of which the two most important are the International Code of Zoological Nomenclature (ICZN) for animals and the International Code of Zoological Nomenclature for algae, fungi and plants (ICN) for plants.
Hence, the answer is - 'Genus and species'.