As the name you see, these bay lights are often used with lower ceilings in open areas. Low bay lights are often designed to illuminate open areas with ceilings between 12 ft to 20 ft. Anything lower is very uncommon in large open area facilities, and would otherwise require a different type of light fixture entirely.
In short, the height in which these lights are used is the main difference in terms of their application differences. For technical differences, there are two main things: lumen output and how they direct their light. Commonly with lower lights, they will require less lumen output due to their nature to lose less light. Secondly, the reflector or lens angles vary greatly as different heights call for different direction and placement of light.
High bay ceiling: 20ft-45ft
Low bay ceiling: 12ft-20ft