Residency is a stage of graduate medical training. A resident physician or resident (also called a house officer / senior house officer in the United Kingdom and several Commonwealth countries) is a person who has received a medical degree (MD, MBBS, MBChB, BMed, DO), Podiatric degree (DPM, BPod), Dental Degree (BDS, DDS, BDent, DMD, BChD, BDSc) and who practices medicine under the supervision of fully licensed physicians, usually in a hospital or clinic. Residencies are also available, and may be required for, students graduating from pharmacy, dental, or podiatric schools. Residencies are optional for students graduating from optometry school.
A residency may follow the internship year or include the internship year as the first year of residency. The residency can also be followed by a fellowship, during which the physician is trained in a sub-specialty. Successful completion of residency training is a requirement to practice medicine in many jurisdictions.