CPAP devices, or Continuous Positive Airway Pressure devices, are machines used to treat sleep apnea, a condition where breathing repeatedly stops and starts during sleep. These devices work by delivering a steady stream of air through a mask that keeps the airway open, allowing for uninterrupted breathing throughout the night. The use of CPAP devices can significantly improve sleep quality and reduce daytime fatigue for individuals with sleep apnea. They come in various styles and sizes, and many modern models are equipped with features like humidifiers and adjustable pressure settings to enhance comfort and effectiveness.