An automated external defibrillator (AED) is a portable medical device designed to treat individuals experiencing sudden cardiac arrest. It works by analyzing the heart's rhythm and delivering an electric shock, if necessary, to restore a normal heartbeat. AEDs are user-friendly, featuring voice prompts and visual instructions to guide users through the process, making them accessible to people without medical training. AEDs are commonly found in public places such as schools, airports, and shopping centers, ensuring quick access in emergencies. They are an essential part of cardiopulmonary resuscitation (CPR) efforts, increasing the chances of survival for individuals in cardiac distress when used promptly.