Nomenclature is a system of names or the rules for forming terms within a particular field — the act or process of naming, and the resulting system by which names are assigned.

The concept is most rigorously developed in biological classification, where nomenclature governs how species are formally labeled. The Linnaean system of binomial nomenclature, established in the 1750s by Carolus Linnaeus, assigns each species a two-part Latin name: a generic name identifying its genus, and a specific epithet distinguishing the species within that genus. Beyond biology, nomenclature applies to any field that needs a consistent naming convention — software architecture, chemistry, tagging systems — where the goal is the same regardless of domain: a name should uniquely and predictably identify what it labels.