When choosing between a low bay light and a high bay light, the most important factor to consider is the height of  the ceiling where the light will be mounted. 

Typically, a low bay light is  used where the ceiling height is between 15 and 25 feet.  High bay lights are used with ceiling heights of 20 to 40 feet .  The illumination of light will differ between high bays and low bays and it is always important to choose the right one.