White balance is the function that makes white things look white in a photograph, by compensating for the influence of the color of light in the shooting environment.
Different lights have different colors and characteristics. For example, incandescent lights have a yellowish color, and the sunlight on a cloudy day has a bluish cast. Human eyes can automatically compensate for this influence, based on the concept that "white things should look white." However, in a photograph, a camera reproduces the color it captures as is. As a result, depending on the ambient lighting, white may look yellowish or bluish in a photograph, compared to the actual image seen by the naked eye.
In photograph , white dishes look yellowish because of the incandescent light. On the other hand, photograph  has a bluish cast because of the sunlight.
White balance's original function is to adjust the standard of "whiteness" in the camera, to correct for "color casting" like this that is caused by the color of light. In addition to this function of reproducing whiteness, the white balance function in digital cameras is increasingly used as a color filter to adjust color tones as well.
Auto white balance (AWB)
The camera has an "auto white balance (AWB)" function, which adjusts white balance automatically according to recognized scenes. Because the white balance function of the camera is set to AWB by default, it automatically adjusts the color of photographs to look natural in various scenes. For snapshots, or in conditions with mixed lighting, when you don't know which white balance setting is suitable, it is recommended that you start with AWB.
Changing the white balance setting
In addition to AWB, several white balance settings suitable for various scenes are preset in the camera. If you are having difficulty getting the expected color with AWB, or you want to adjust color tones according to your preferences, you can manually select the desired white balance setting.
As shown in the figure above, 10 white balance settings, including AWB, are preset in the camera. The following photographs show the color difference using different white balance settings.
AWB Daylight Shade Cloudy
The cat was photographed on a cloudy day. With [AWB] and [Cloudy], colors were reproduced naturally, close to the actual colors. In comparison, the photograph looks more bluish with [Daylight], and more yellowish with [Shade].
[AWB] [Fluorescent: Warm White (-1)] [Fluorescent: Cool White (0)]
[Fluorescent: Day White (+1)] [Fluorescent: Daylight (+2)]
Now, let's compare the night view shots above. Here, [AWB] reproduced the actual colors quite well, but there is a slight green cast on the entire image. By changing to [Fluorescent], the entire green cast went away. Among the [Fluorescent] settings, you can see that the colors become warmer as the setting is changed from - to +. Select the setting based on your preferences or the image you want to capture.
Each white balance setting can be fine-tuned (*). By fine-tuning the preset white balance settings, you can add your own touch to your photograph.
(*) White balance settings that can be fine-tuned and the operation screen vary by model.
The photograph on the right was shot by adding a blue tinge to the [AWB] setting.
Using the fine-tuning function made it possible to render color that cannot be achieved using the preset white balance settings.
White balance: [AWB]After fine-tuning