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...You're 18 and you've never heard the term? I mean, when I was in 9th grade we took three CPR classes. Heck, I'm even certified.
You know, it's like mouth-to-mouth resuscitation? Medics also have stuff that act in a similar way so they don't have to put their mouths on the victim.
If you're asking what the acronym stands for, it's Cardiopulmonary Resuscitation.