What exactly is the difference between an RN, a LPN, a GNP and a CNA?

RNs They perform a variety of duties including providing treatments, educating patients and their families about various medical conditions, and providing advice and emotional support to patients and family members.

LPNs work in all areas of health care, and have more training than CNAs, but less than RNs. LPNs provide basic bedside care such as taking vital signs, preparing and giving injections, applying dressings and ice packs, and monitoring the patient's overall condition.

CNAs provide patients with assistance in their daily living tasks, working under the supervision of a registered nurse.

http://www.career-opportunities.net/articles/view/different_types_medical_nurses


A Nurse Practitioner (NP) is an advanced practice nurse who has completed graduate-level education (either a Master's or a Doctoral degree) and training in the diagnosis and management of common as well as complex medical conditions.
Gerontology (GNP)

https://en.wikipedia.org/wiki/Nurse_practitioner