The "batch" command allows you to automatically process one ore more files. This is useful, for example, in resizing multiple images and saving them, automatically.
White balance describes how overall color cast of your image. Properly adjusted, the light should be neutral (white), therefore correcting the white balance of a photo that has too much yellow means removing that excess yellow in the lighting.
white balance to a whole folder of images. No longer will you have to do repetitive color correction one photo at a time!