A water softener is comprised of four basic parts:
The four parts that make up the water softener help filter out calcium and magnesium through softening cycle and a regeneration cycle. During the softening cycle, hard water enters the softener through the valve and passes in the resin tank, where thousands and thousands of little resin beads sit. These resin beads are negatively charged and attract the calcium and magnesium particles that pass through. Soft water, or water without the calcium and magnesium, is what is left and what then flows throughout the rest of the house.
The resin beads that have become coated with calcium and magnesium have to be cleansed. During the regeneration cycle, the beads are cleansed with a strong salt solution from the brine tank. Once the resin beads are cleansed with the salt solution, the cleansing rinse is washed down the drain, along with the calcium and magnesium particles.