Rescue Breathing is a lifesaving technique used when someone is not breathing or not breathing normally. It involves giving breaths to the person to provide oxygen until emergency help arrives or they start breathing on their own. This method is often used in cases of cardiac arrest or drowning. To perform rescue breathing, first ensure the scene is safe, then check the person's responsiveness. If unresponsive and not breathing, tilt their head back slightly to open the airway, pinch their nose, and give two breaths, each lasting about one second. Continue with cycles of rescue breaths and chest compressions if necessary.