Magic Forums

Okay, I have a question about "visualization". I have heard several interpretations of vizualtization, but I am slightly confused on one factor. I've heard vizualization is actually seeing, for instance, a flame instead of imagining it. But is imagining it with a notmal mental image like what you would get from reading a book sufficient? The "actually seeing" the flame in your minds eye like it is a tangible thing confuses me. I would definitely accept the possibility of that, but how would one come to a state like that? It sounds like no easy thing. I hope that makes sence. Can anyone explain?
Thanks. :)