Satoshi Nakamoto is believed to be the creator of bitcoin itself, but we still don't know.
Satoshi Nakamoto could be a group or organization, not a single individual.
in my opinion, satoshi nakamoto is real but I don't think that satoshi nakamoto is just one person. I think satoshi nakamoto is a group of some people which a high skill in cryptocurrency and internet and they do one project which is bitcoin project. and they contribute to the bitcoin project from the beginning until now and I guess they still watching and giving contribute by secretly. they will use their skill to develop more in bitcoin code and will stay behind the wall without telling who they are.