Although you can freeze, can or dry apples to preserve and store apples, the best method usually involves sugar - this keeps the apples from browning and helps them stay firmer. There are two main ways of preserving apples in sugar
Dry packing apples in sugar - a simple method where you add ½ cup of sugar to every quart of cut apples, mix and seal in your freezer bags.
Canning apple slices in syrup - a great method where you make a simple syrup recipe which you allow to cool before you simply drop your apples in and send them off to the freezer.