Water softening is the filtering and removal of magnesium, calcium, and other metals. It's the process in which hard water turns to soft water.
When hard water passes through the softening system's resin bed, the calcium and magnesium (hardness) ions are removed through an ion exchange process, so only softened water passes through to your home. Once the resin bed fills up with hardness ions, it must be regenerated (cleaned). Salt is typically used in the regeneration process and restores the resin to a "clean" state so the ion exchange process can begin again.
Health benefits of softer warder include:
No more dry skin
Hard water causes soap to build up on the surface of your skin when you shower. This is due to the magnesium and calcium found in the water. Soft water filters these contaminants out and thus leaves your skin feeling cleaner and softer.
Cleaner Clothes
Like on your skin hard water decreases the lathering of your laundry detergent making it less effective in cleaning your clothes. Most reports show that softer water saves anywhere from 50-70% of your laundry and dishwasher detergent.