Mineral deposits (water spots) form when wash water or rainwater dries on the paint before you have a chance to wipe it off, leaving white spots from minerals dissolved in the water on the surface. If you repeatedly leave the spots to dry in the sun, the minerals can etch slightly into the paint, and simply wiping them with a cloth will no longer remove them.
Descaler is a product specifically designed to dissolve these deposits – spray it onto the dried spots, leave it to work briefly, then rinse it off. Alongside the standard Descaler, you can also find Gyeon Q2M WaterSpot, or Koch Chemie Finish Spray Exterior, which combines water spot removal with a finishing detailer function.
