"You don't take a photograph, you make it"
--Ansel Adams 
HDR images enable photographers to record a greater range of tonal detail than a given camera could capture in a single photo.  HDR photographs are generally achieved by capturing multiple standard photographs, often using exposure bracketing, and then merging them into a single image. 

One of the exciting things about HDR photography is the ability to “trick" your brain into experiencing much more than a normal photograph--often evoking deep memories and emotions in a tangible way.