CPAP (Continuous Positive Airway Pressure) as the name suggests, provides continuous pressure to the upper respiratory tract of the patient during inspiration and expiration.
It is used e.g. for the treatment of sleep apnoea and pulmonary oedema.
BiPAP (Bi-level Positive Airway Pressure) provides different levels of pressure during inspiration and expiration.
This type of NIV may be used to support breathing in e.g. COPD exacerbations.