Here are some of the places where high bay lighting is commonly used:
Round (UFO): Has a saucer-like shape where there is only one contact point with the ceiling. They provide a wide beam angle. UFO high bay are ideal for use in large, open spaces such as warehouses and factories.
Linear: These come in various widths and are mounted to the ceiling with a huge cable or chain. They provide rectangular, narrow illumination. Making them ideal for use in smaller spaces such as retail stores and offices.
Vapor Tight: Sealed from weather or harsh elements such as dirt or moisture. These fixtures are typically linear and are often mounted to the ceiling. Making them ideal for harsh environments.