PEEP, or positive end expiratory pressure, is a concept performed by the patient, where their lips purse up when they breathe out (exhalation). By doing this, the patient is able to keep their bronchioles and alveoli open. Humans are able to do this naturally when they are in respiratory distress. Still, we have a special tool that we can use to help treat this patient.
CPAP. CPAP is a device that is placed over the patient's mouth and nose, and forces air into the patient's lungs. This device basically takes over the patients normal PEEP response.