Hydroponics is a method of growing plants using mineral nutrient solutions, in water, without soil. Terrestrial plants may be grown with their roots in the mineral nutrient solution only or in an inert medium, such as perlite, Clay pebbles, rockwool, or coconut husk.
There are 5 basic types of hydroponic systems, Wick, Water Culture, Ebb and Flow (Flood & Drain), Drip (recovery or non-recovery) and N.F.T. (Nutrient Film Technique). There are hundreds of variations on these basic types of systems, but all hydroponic methods are a variation (or combination) of these five.