An automated external defibrillator (AED) can save lives during sudden cardiac arrest by restoring the heart's normal rhythm through defibrillation. AEDs are easy to use as they provide automated voice instructions to guide the user through the process without requiring training. To operate an AED, one should first check if the victim needs CPR and then turn on the AED, apply its pads to the victim's bare chest, and follow any voice instructions without touching the person until paramedics arrive.