Miele Water-Softening Salt is for use in Miele and other brand dishwashers which have water softeners built into them. Tap water often contains lime. So that lime is not deposited on dishes and the dishwasher, your dishwasher may have a water softening unit which withdraws the harmful lime from the water. This is a 3.3 lb. (1.5kg) package.
Table salt is unsuitable for water softening in dishwashers. It may contain insoluble components affecting the efficiency of the water softening unit.