Continuous Positive Airway Pressure (CPAP)
The key feature is, there is no breath support. There is some PEEP being delivered, but generally its up to the patient to fight the tubes of the circuit to suck air from the cold indifferent ventilator. With no help whatsoever.
In fact, you can even turn the PEEP off.
Also... CPAP is not PEEP. The two are not equivalent. CPAP is a spontaneous mode of ventilation with a continuous positive pressure maintained throughout the respiratory cycle- both expiratory and inspiratory. PEEP is a variable of the ventilation cycle, the positive pressure maintained at the end of expiration. CPAP has PEEP as a setting.