White balance for incadescent lighting. It gives off a blue hue, obviously, to balance the yellow/orange hue the incadescent light gives off.
White balance for daylight.
White blanace for flourescent light.
White balance for cloudy, which adds a warming filter.
I am bad about forgetting about the white balance, an effect that is crucially important. I am training myself to keep it on auto, just in case I fire one of those once in a lifetime shots without checking all of my settings. I prefer to set it myself as the white balance can completely change the look of a picture.