White Balance is when you change the color of your camera to ensure that things that are white show up as a true white color on your video/photo. Things like certain lighting can change how colors are perceived through the camera, so it is important to change these settings accordingly. These different color temperatures can cause a blueish, yellowish, and greenish hue to be over your image if the setting is not changed. Most cameras have an Auto White Balance setting that does everything for you. If not, then you can select certain presets for varying light situations and can even select the Kelvin value on your camera.