Defibrillators are life-saving medical devices used to restore normal heart rhythm in individuals experiencing sudden cardiac arrest (SCA). They work by delivering an electric shock to the heart, which helps reset its electrical activity and allows it to beat normally again. There are two main types: automated external defibrillators (AEDs), designed for public use and requiring minimal training, and manual defibrillators, typically used by healthcare professionals in hospitals. AEDs are equipped with sensors that assess heart rhythms and determine if a shock is necessary, providing simple voice or visual instructions for users. Defibrillators are crucial because timely defibrillation, often within minutes of cardiac arrest, significantly increases the chances of survival. Having AEDs readily available in public places like schools, airports, and workplaces can make a critical difference in emergency situations.