Obstructive Sleep Apnea, or OSA, is when the airway gets blocked during sleep.  When the muscles in the back of the throat and tongue relax, they fall back and can stop airflow.  This repetitive choking is terrible for you.  Oxygen levels drop, sleep is fragmented, and not only can it cause snoring and restless sleep, but also excessive sleepiness during the day, headaches, and memory issues.  It increases the risk of heart attack, stroke, diabetes, and even car accidents.
The traditional treatment for OSA is positive airway pressure, commonly called CPAP.  It can work well, but is commonly very hard to use regularly for a variety of reasons.  Patients need options beyond Positive Airway Pressure.