Why is water important to your body?

Your body uses water in all parts inside your body, water provides an efficient way to transfer substances from a cell to the cell's environment, your body also uses water for your organs, and tissues, it also can be helpful to your skin so it's healthy, so I don't think you can live without it.

Please correct me if I'm wrong :)

it's diluted or concentrated

in a diluted solution, you can add a lot more solute but in concentrated only a little more can be added