Like "A sleep mask looks alot like an oxygen mask. The mask covers part of the nose or some cover the nose and mouth. They are connected to what's called a cpap machine. It provides forced air to keep your pulse ox levels normal. Some people who snore have sleep apnea but most do not. The mask and cpap machine are used to help you breath more deeply and get into the REM sleep cycle where you get the important deep sleep we need. Hope that helps although it's probably more than you wanted to know! taz2020"