In the graph below, you can see how I slept for the full duration of the night, cycling between N1, N2, N3 and REM sleep, as well as periods of wakefulness. In general, this shows excellent sleep ...

That’s how Apple defined it in testing: If an EEG said a person was in stage 2 ... This stage makes up most of what Apple reports as your core sleep. N3 is often called “deep” sleep, and ...

Deep sleep plays an important role in learning and memory storage, "by facilitating a process called 'memory consolidation,' ...