A CPAP machine, or Continuous Positive Airway Pressure machine, is a medical device used to treat sleep apnea, a condition where a person's breathing repeatedly stops and starts during sleep. The machine works by delivering a steady stream of air through a mask that keeps the airway open, allowing for uninterrupted breathing throughout the night. CPAP machines come in various types and sizes, often featuring adjustable pressure settings to suit individual needs. They are typically recommended by healthcare providers after a sleep study confirms the presence of sleep apnea, helping improve sleep quality and overall health for those affected.