Ultimates confusion

Sorry to have to ask, but the internet is not helping. I collected comics in simpler times 1975-1995.

i recent got back to the hobby & find some things extremely confusing, mostly this whole Ultimates business.

My main questions are, Mark Millar's Ultimates... does that take place in the same universe as Al Ewing's Ultimates? Why is Al's called Ultimates 2?

Do these teams operate in the same universe as Morales & Spider-Gwen?!?

Please explain to me as if I was a 5 year old. Lol