Its taking a lot of photos of the same thing with different exposures and then using a program like Photomatix to put those photos into one. High Dynamic Range.
If you take a photo that is bright in some areas and dark in others this will help the photo be properly exposed throughout the photo.
I started here...
took a whole bunch more till I was here...
and put them in Photomatix and ended with this...
someone else should explain cause I suck.