When a hydroponic system is built to remain perfectly level. That is the basics of level hydroponics
Level hydroponics is when a hydroponic grow system is built level from one end to the other in all directions.
A hydroponics support system is any support system that holds up a hydroponic unit.
When a hydroponics system needs a support, the hydroponics support holds it in place. It can be one level, or stacked on top of each other.