General anesthesia is a state in which a patient's consciousness and sensations are temporarily suspended or reduced, allowing for surgery or other procedures to be performed without causing pain or discomfort. It involves administering medication that affects the central nervous system, typically through intravenous injection, so that the individual is unable to feel any pain or remember the procedure afterwards. General anesthesia can also have effects on various bodily functions such as heart rate and breathing, which are closely monitored by medical professionals during the process.