Minimum alveolar concentration (MAC) is a measure used in anesthesia to determine the potency of inhaled anesthetic agents. It represents the concentration of an anesthetic in the lungs that prevents movement in 50% of patients in response to surgical stimuli. A lower MAC value indicates a more potent anesthetic. MAC is influenced by various factors, including age, body temperature, and the presence of other medications. Understanding MAC helps anesthesiologists select the appropriate dosage of anesthetics, ensuring patient safety and effective anesthesia during surgical procedures.