OK, this probably always going to be one of the trickier things to understand, particularly if English isn't your first language, because some of the terminology is, err, terminological. So, no need to get 'mad'.
If that is exactly what wikipedia says, it is a mis-statement; usually
dominant is zero, but that doesn't mean that it fundamentally has to be. It is certainly most convenient in the standard implementation, but you could implement a completely inverted system, if you were using a different networking medium.
It is vitally important to note that, even in that variant case, that descriptions in terms of dominant
remain valid, where descriptions in terms of highs and lows would need to be inverted (that is, you would have to replace 'high' with 'low' and 'low' with 'high'). As the CAN specification itself does not specify a single transmission medium, this distinction is important in a few cases, if not in the 'default' one.
I can now suggest to you:
(the first has nice diagrams, and is easy to understand, but the part that you want is some distance in)