General anesthesia is a treatment that renders you unconscious during medical procedures, so you don't feel or remember anything that happens. General anesthesia is commonly produced by a combination of intravenous drugs and inhaled gasses (anesthetics).
The "sleep" you experience under general anesthesia is different from regular sleep. The anesthetized brain doesn't respond to pain signals or surgical manipulations.
The practice of general anesthesia also includes controlling your breathing and monitoring your body's vital functions during your procedure. General anesthesia is administered by a specially trained physician, called an anesthesiologist, often in conjunction with a certified registered nurse anesthetist.