White balance (WB) is for making the white areas look white. Normally, the Auto [] (Ambience priority) or [] (White priority) setting will obtain the correct white balance. If natural-looking colors cannot be obtained with Auto, you can select the white balance to match the light source or set it manually by shooting a white object.
White Balance
The human eye adapts to changes in lighting so that white objects look white under all kinds of lighting. Digital cameras determine white from the color temperature of lighting and, based on this, apply image processing to make color tones look natural in your shots.