Bracketing Camera Exposure Part #2 - Why do I need to Bracket Exposures?

[klakfi]

I currently use a NikonD90, with which I have done bracketing. However, on my Nikon D50 the 3-frame bracketting was done with one shot - one shutter click. With the Nikon D90, are we limited to having to shoot three different frames separately, or does the Nikon D90 have a feature where you can shoot all three different exposures with one shutter click, as in the D50?

Thank you.