I had a discussion with a fellow photographer the other day and the topic of "why I bracket my photo's" came up.
Bracketing involves taking multiple exposures of the same scene. I do this because, in my opinion, the camera is limited in its dynamic range. It cannot properly read a scene that has a bright sky, while there is a dark foreground. The camera's dynamic range is limited. You can get close, but when I photograph a grand landscape, there is a considerable difference between the light from the ground and the light from the sky.

So, when I take photographs, I take extra pictures knowing that I will be combining them in photoshop to produce the optimum image.

Yes, I could use a single exposure and brighten the dark areas and decrease the bright areas, but this produces one major issue. NOISE!. When you try to adjust for the dark and light areas, the images starts to get grainy and appears to be dirty. 

<a href="http://fineartamerica.com/art/all/scenery/framed+prints" style="font: 10pt arial; text-decoration: underline;">scenery framed prints</a>