[Déjà Bru]

I am confronted today with this array on the Sports Media web site:

I am prompted to finally ask, what are the differences among these racing circuits?

I am vaguely aware that there is a big difference between the types of race cars in NASCAR versus the others. But what about IndyCar v. Formula 1? Is it like leagues or rival organizations like PGA and LIV?

What else? What defines NASCAR v. IndyCar v. Formula 1? Any help to promote understanding would be appreciated.