A name in the Italian language consists of a given name (Italian: nome) and a surname (cognome); in most contexts, the given name is written before the surname, although in official documents, the surname may be written before the given name or names.
Italian names, with their fixed nome and cognome structure, differ from the ancient Roman naming conventions, which used a tripartite system of given name, gentile name, and hereditary or personal name (or names).
The Italian nome is not analogous to the ancient Roman nomen; the Italian nome is the given name (distinct between siblings), while the Roman nomen is the gentile name (inherited, thus shared by all in a gens). Female naming traditions, and name-changing rules after adoption for both sexes, likewise differ between Roman antiquity and modern Italian use. Moreover, the low number, and the steady decline of importance and variety, of Roman praenomina starkly contrast with the current number of Italian given names.[1][2]
In Italy, one portion in person's name may be determined by the name day (onomastico). These name days are determined according to the sanctorale, a cycle found in the General Roman Calendar, which assigns to a day a saint (or as to the great majority of days, several saints), so that different names often are celebrated on that day.[3] Traditionally, parents fix the name day of their child at christening, according to their favourite saint; in case of different ones (on different days) with the same name; that child will carry it throughout life. In the case of multiple given names, the child will celebrate only one, usually the first.