An operating theater, also known as an operating theatre, operating room (OR) or operating suite, is a facility within a hospital where surgical operations are carried out in a sterile environment. Historically, the term “operating theatre” referred to a non-sterile, tieredtheater or amphitheater in which students and other spectators could watch surgeons perform surgery. Several operating rooms are part of the operating suite that forms a distinct section within a health-care facility. Besides the operating rooms and their wash rooms, it contains rooms for personnel to change, wash, and rest, preparation and recovery rooms(s), storage and cleaning facilities, offices, dedicated corridors, and possibly other supportive units.