It's likely you know at least a little something about continuous positive airway pressure, more widely known as CPAP.
It involves wearing a mask which delivers air to you as you sleep so that you don't have dangerous pauses (called apneas) in your breathing.
CPAP is only one of several kinds of therapeutic devices using positive airway pressure (PAP) therapy to treat sleep apnea. A second kind of therapy known as Bilevel PAP (BiPAP) also exists which helps people with severe sleep breathing disorders.
Which is the right therapy for you? You'll know that answer once you understand the differences between the two: how they work, what problems they address, and who they're intended for.