In caramell or crystal malts, the maltoz melts due to heat. When it cools down, the sugar dryes in crystals, this is wher names comes from. Some part of this sugar will not ferment, giving sweetness, and maybe toffifee, buiscuit aroma to beer. It also improves body and head retention of finished beer. There are no enyimes in caramell malts, use 5-10% of the whole grain bill. Different manufacturers gives different fantazy names for them, usually name reflects of the colour of the malt.