Training and education requirements and healthcare professionals are often defined by state licensing boards. These board are made up of other healthcare professionals who determine level of skills, competency and education needed to perform certain tasks. This is called scope of practice.
The field of nursing is a good example. A CNA (certified nursing assistant) has six weeks of training and education. An RN, however, has at least two years of education and training. Therefore, the RN has a greater level of responsibility than a CNA. A Nurse Practitioner, generally holds a masters degree, which consists of nearly six years of education and training. A nurse practitioner can see patients independently or under the supervision of a physician.