Hard water contains calcium and magnesium. Your Kinetico 2020c contains resin beads, which hold sodium ions.When hard water passes through the resin beads inside a Kinetico 2020c, the beads attract and hold the calcium and magnesium ions in exchange for sodium.After this ion exchange process, the water leaving your Kinetico 2020c is soft (fig.1).
Once the resin bed is loaded with calcium and magnesium ions, it must be cleansed (or regenerated) so that it can continue to soften water. The salt in your salt storage tank mixes with water to wash the resin beads. The brine solution loosens the hardness minerals which have built up on the resin beads; then the system backwashes and flushes the hardness minerals away.
Once this is complete, the resin beads hold sodium ions. The system is again ready to exchange the sodium ions for more calcium and magnesium ions.
The Kinetico 2020c regenerates with soft water. Since you already know what a difference cleaning with soft water can make throughout your home, it only makes sense that the Kinetico 2020c cleans itself with soft water too. And your system uses only clean, soft water to make the salt solution in the salt storage tank.