Adjusting the white balance is to get the colors in your images as accurate as possible.
Why would you need to get the color right in your shots?

You might have noticed when examining shots after taking them that at times images can come out with an orange, blue, yellow etc look to them – despite the fact that to the naked eye the scene looked quite normal. The reason for this is that images different sources of light have a different ‘color’ (or temperature) to them. Fluorescent lighting adds a bluish cast to photos whereas tungsten (incandescent/bulbs) lights add a yellowish tinge to photos.

White-Balance
The range in different temperatures ranges from the very cool light of blue sky through to the very warm light of a candle.

We don’t generally notice this difference in temperature because our eyes adjust automatically for it. So unless the temperature of the light is very extreme a white sheet of paper will generally look white to us. However a digital camera doesn’t have the smarts to make these adjustments automatically and sometimes will need us to tell it how to treat different light.


So for cooler (blue or green) light you’ll tell the camera to warm things up and in warm light you’ll tell it to cool down.