It is a procedure applied by an anesthesiologist and is the name of a series of medical applications developed to ensure that the patient does not feel pain during the operation, including before and after the operation, to tolerate the intervention, not to remember the process after the operation, and to provide comfort. In addition, it is the duty of the anesthesiologist to maintain the health and safety of the patient during the operation. It can be applied as general, regional (regional) or local anesthesia.