Cardiopulmonary Resuscitation (CPR) is a lifesaving technique used in emergencies when someone's breathing or heartbeat has stopped. It involves a combination of chest compressions and rescue breaths to help maintain blood flow and oxygen to vital organs until professional help arrives. CPR can be performed by anyone, even without medical training, and knowing how to do it can make a significant difference in saving a life. When performing CPR, it's important to call for emergency services first. Then, place the heel of one hand on the center of the person's chest, interlock your fingers, and push down hard and fast. Remember to allow the chest to rise fully between compressions.