An Automated External Defibrillator (AED) is a portable device used to treat people experiencing sudden cardiac arrest. It analyzes the heart's rhythm and can deliver an electric shock, if necessary, to restore a normal heartbeat. AEDs are designed for use by laypersons and provide voice prompts to guide users through the process. These devices are commonly found in public places such as schools, airports, and shopping centers. They are crucial in emergencies, as immediate defibrillation can significantly increase the chances of survival. Training in AED use is often included in CPR courses, promoting awareness and preparedness in the community.