It is confusing, actually, because apparently not enough is known about this. A German gynaecologist by name of Ernst Gräfenberg thought he had discovered a point (of vary varied size in various women) on the upper side of the vagina that was good to stimulate. Many talk about it, but it has never been scientifically proved that is exists. However, it is said that around this point, some (by no means all) women have some sort of glands like men's prostata. Stimulation of these glands by the help of stimulating the G point can produce a liquid rather like semen, but without the spermatozoer. It is called female ejaculation. But confusingly it doesn't always, apparently, why is not know!
So, while the G point is not proved, the existence of these glands is, apparently, and female ejaculation does exists, but only for those with these glands and not all of those.
I can see the fun of trying to find out if you have this ability ;-)
But don't make it the only hallmark of wonderful sex, or feel bad if you cannot.