High bays, low bays and floodlights are industry standard terms for the more heavy duty types of light fitting. We will outline the main differences and uses below.
High bays are designed to be used in very high areas (approximately 8m and greater) to provide well distributed and uniform light for open areas. The key element of the fitting which will help guarantee the correct light output is the reflectors and optics used by the fitting. A particular consideration for use with a high bay is if it can light vertical surfaces as well as it can illuminate the floor, or working plane. Lighting of verticals is particularly important when dealing with warehouses where items are required to be picked from a shelf.
Low bays work in much the same way as a high bay, but will be best suited to lower mounting heights. The main differences will be in the lamp types selected and the types of reflectors and optics used.
Flood lights are a very versatile method of illuminating areas where a conventional mounting arrangement may not be an option. The flood light will have an asymmetric throw of light which can be angled into the space to be lit. Care and consideration of glare should be taken when designing with floodlights, due to the brightness of the fitting and the fact it may be angled close to horizontal