anyone know the process of putting on snow white's long hair on ginny goodwin?

ever since the beginning of the series, i've always been curious how they were able to put on the long snow white hair on ginny and make it look so incredibly real! i mean is it a wig? extensions? and how is it that when they take it off, her bangs are able to continue to stay the same? i mean it looks like when she has it on, they seperate both sides of the bangs and somehow make it look so much like she really does have long hair! at times i've thought the pixie cut was a wig lol i mean i've seen photoshoots she's done as snow and seen her in the episodes where the front of her hair looks like its part of the long hair and not just combed back o combed side to side. seriously, how do they do this?! i'm not complaining mind tu i just really wanna know! :)