Ask HN: What is the present moment?

When reading, I often encounter the “present moment”, and a recommendation to live in/for it. To not dwell on past or future, but on this moment alone.

When I actively try to do this, it’s hard to define exactly what it is. I can only comprehend that which has happened (albeit very recently), and so it is really the near-past in which I’m focusing. What is the bounds of the present moment where the human experience is concerned?

And theoretically, if there were a super intelligence who could easily capture and process all information in the present, would their present moment start expanding into the future and the past? Does the present moment have a bandwidth of some kind depending on the subject? What is it exactly?