White balance is a camera setting that adjusts the colors in your image to make them look more natural. It does this by compensating for the color temperature of the light source in your scene, which can vary from warm (yellowish) to cool (bluish).

Incorrect white balance can cause color casts in your photos, making them look unnaturally warm (orange or yellow) or cool (blue). For example, if you're photographing a white wall under incandescent lighting without adjusting your white balance, the wall might appear orange in your photo. Similarly, if you're photographing outside on an overcast day without adjusting your white balance, your image might have a blue cast.

You can set white balance manually or use automatic white balance (AWB) where the camera makes its best guess based on the scene. Many cameras also have preset white balance modes for different conditions, like daylight, cloudy, shade, tungsten, and fluorescent.

In post-processing, especially with RAW files, you can adjust the white balance to your liking or to accurately represent the scene's colors.