Water Softeners: Water softeners remove calcium and magnesium from the water through ion exchange. You fill the water softener’s mineral tank with small beads that hold a negative charge. That negative charge attracts the positively-charged calcium and magnesium ions. Then the system flushes salt through the beads. The salt collects the minerals as it flows down the drain. Once the minerals are gone, water spots should go away and your soaps should work better. On top of that, people with skin issues might have an easier time showering with a water softener.
Water Conditioners: Water conditioners don't remove the minerals from your water. Instead, they often adjust the PH of the water and coat the minerals. That coating prevents the minerals from sticking to pipes or dishes. Another type of water conditioner is a Poly-Phosphate filter. These methods can help reduce water spots and protect water fixtures. But they often don't do as good of a job as a water softener since the minerals are still in the water. On the upside, they don’t leave your skin feeling slippery, as soft water might.