Teaching hospitals are specialized medical centers dedicated to educating and training future and current health professionals, typically affiliated with universities and often co-located with medical schools. They utilize structured residency programs to allow qualified graduates, including physicians, dentists, and pharmacists, to practice medicine safely under the direct supervision of senior clinicians like attending physicians. Historically, the first known teaching hospital was the Academy of Gundishapur in the Persian Empire during the Sassanid era. Early examples also include the Islamic Bimaristans, such as the Al-Fustat Hospital founded in Cairo in 872 and the Al-Adudi Hospital established in Baghdad in 981, which pioneered systematic patient practice under physician guidance. Within these institutions, various roles exist, from medical students and interns to residents undertaking specialized training, all overseen by attending physicians who provide both care and instruction.