Hydroponics is a technique of:
Cultivation of plants in a defined nutrient solution in complete absence of soil
Plants produce their own food, but require certain elements for their proper physiological functioning. These are usually absorbed from the soil through the roots. Soil also provides a firm place for anchorage. But if the support for anchorage is take care of; plants can be grown in a nutrient solution containing all the essential elements in optimum concentrations. Thus, the technique of hydroponics attempts to grow plants in a defined nutrient solution in complete absence of soil.