High Dynamic Range/HDR photography is a digital technique which uses specially designed computer software [Photomatix, Photoshop, Artizen] to combine multiple exposures of the same scene to digitally expand the dynamic range, [range of tones and shades in an image] to create an image with details in both the highlights and shadows similar to which can be observed in the real world.
For more information visit • Wiki HDR Page • HDRSoft.com