When using the hydroponic system, the grower does not depend on soil to support plants and supply nutrients. You would rather depend on a selected hydroponic media to provide support for the roots and maintain water content. While there are different systems of hydroponics you should know about, these systems work on the basis of suitable materials.
The growing medium of hydroponics involves a system where the plant growing medium takes the place of soil. The medium does not act as a nutrient provider like the soil but serves as a support to keep the plant upright.