HDR stands for High Dynamic Range, and it's a way to photograph where you take several pictures of the same scene and then merge them together. When you do this, you get an incredible mix of the darkest darks and lightest lights. The ideal way to do this is with a tripod, using some special software. Sometimes (well, alot of the time) HDR photos can look overly fake. I like HDR images that enhance the photo but don't take it into the crazy world of surrealism (a.k.a. bizzaro-land).