What's a Nap, What's Sleep?

[VaughanJB]

A moment ago I noted I had taken a nap this morning. Even when I was writing it my mind was going back and forth on my use of the word - my "nap" lasted around 90 minutes or so.

So, given it's 2026 and AI knows everything and we can't/shouldn't comment unless we get its point of view (that's a touch of humor, by the way) I thought I would take a look at what constituted a nap over an old fashioned sleep.

"The ideal nap for adults is 10 to 20 minutes (a "power nap"), which boosts alertness without causing post-nap grogginess. Longer naps (60–90 minutes) are best for deep recovery, while 30-minute naps can improve memory but may lead to slight grogginess, according to the National Sleep Foundation. [1, 2, 3, 4]"

I've not been able to find anything that truly defines sleep (as opposed to a nap) in duration terms.

When I was at the peak of my working life, I was king of the "power nap" and would use the technique daily. Can't seem to do it any more.

Where do you draw the line? When is a nap, a sleep? When is sleep, a nap?