Mediums

I understand that using a medium is pretty much what constitutes hydroponic growing, but I was wondering why. What about a hydroponic medium is specifically better for the plant?

If they made hydroton with holes and crevices to look somewhat like lava rock, then it would be perfect. It will give more points for the roots to latch on to. The holes and crevices will catch small pockets of water thereby holding more nutrients. But I don't think the medium can be improved more than that, it's the nutrient and oyxgen rich water and pH level that does the wonders.

Large size perlite, silica rocks

A growing medium is a soil replacement used for growing plants. Doesn't have to be just for hydro!