An area code is a three-digit number that helps identify a specific geographic region for telephone calls. It is part of a larger phone number and is used to route calls to the correct location. For example, the area code 212 is associated with parts of New York City, while 310 is used for areas in Los Angeles. When you make a call, you usually need to dial the area code first, especially for long-distance calls. This system helps ensure that your call reaches the right destination, making communication more efficient across different regions and states.