Residency or postgraduate training is a stage of graduate medical education. It refers to a qualified physician, veterinarian, dentist, podiatrist (DPM) or pharmacist (PharmD) who practices medicine, veterinary medicine, dentistry, podiatry, or clinical pharmacy, respectively, usually in a hospital or clinic, under the direct or indirect supervision of a senior medical clinician registered in that specialty such as an attending physician or consultant. In many jurisdictions, successful completion of such training is a requirement in order to obtain an unrestricted license to practice medicine, and in particular a license to practice a chosen specialty. In the meantime, they practice "on" the license of their supervising physician. An individual engaged in such training may be referred to as a resident, registrar or trainee depending on the jurisdiction. Residency training may be followed by fellowship or sub-specialty training. Whereas medical school teaches physicians a broad range of medical knowledge, basic clinical skills, and supervised experience practicing medicine in a variety of fields, medical residency gives in-depth training within a specific branch of medicine.