(October 2014). A registered nurse (RN) is a nurse who has graduated from a nursing program and met the requirements outlined by a country or state licensing body in order to obtain a nursing license.An RN's scope of practice is determined by local legislation governing nurses, and usually regulated by a professional body or council.Registered nurses are employed in a wide variety of professional settings, often specializing in their field of practice.n RN's scope of practice is determined by local legislation governing nurses, and usually regulated by a professional body or council. Registered nurses are employed in a wide variety of professional settings, often specializing in their field of practice.