what is core sleep apple watch

The term "core sleep" refers to the majority of sleep time, which is about 67% on average. It is considered the least restorative type of sleep. Apple Watch can estimate the time spent in each sleep stage, including core sleep, deep sleep, and REM sleep. The average Apple Watch user gets about 49 minutes of deep sleep per night, which is approximately 13% of total sleep time. Core sleep is the most common type of sleep, while deep sleep is the least common. The Apple Watch tracks sleep stages using signals from the accelerometer and heart rate sensor, and it divides sleep into core, deep, and REM stages based on the sleep cycle. To view sleep data on an iPhone, users can open the Health app, tap on the Browse tab, scroll down to Sleep, and tap on D, W, M, or 6M to show sleep data for the day, week, month, or 6 months