CPR stands for cardiopulmonary resuscitation, a lifesaving technique used when someone's heart stops beating or they stop breathing. The person performing CPR pushes hard and fast on the center of the person's chest, about 100 to 120 times per minute, to manually pump blood through the body and keep oxygen flowing to the brain. They may also give rescue breaths to put air into the person's lungs.

When someone's heart stops, brain damage can begin within minutes. CPR keeps oxygenated blood circulating until emergency medical help arrives. You might see CPR performed in movies or TV shows when someone collapses, though real CPR looks less dramatic and requires proper training to do correctly.

Many schools teach CPR to older students, and some communities offer classes to kids and adults. Knowing CPR means you could help save a life someday: a family member, a friend, or even a stranger. The technique works on adults, children, and infants, though the exact method varies by age and size.

The Red Cross and other organizations offer CPR certification courses that teach the proper technique through hands-on practice with special training mannequins. While CPR doesn't always revive someone, it can increase their chances of survival until paramedics arrive with more advanced equipment.