Anesthetic agents are substances used to induce a temporary loss of sensation or awareness, primarily during surgical procedures. They can be classified into two main categories: general anesthetics, which affect the entire body and induce unconsciousness, and local anesthetics, which numb a specific area without affecting overall consciousness. These agents work by blocking nerve signals in the brain and body, allowing patients to undergo procedures without pain. Common examples include propofol for general anesthesia and lidocaine for local anesthesia. The choice of anesthetic depends on the type of procedure and the patient's medical history.