Different light sources appear different colours on camera. The colour can affect the quality and overall mood of the final image. Although in most cases the Auto White Balance on the camera will give great results, sometimes it will give results that you don’t want. The white balance settings allow you to change the image colour balance to the specific lighting conditions.
Using RAW images allows the white balance to be changed in editing software such as Adobe Photoshop or Lightroom.
https://www.digitalcameraworld.com/tutorials/cheat-sheet-white-balance-settings