White chocolate: Like milk chocolate, this is made of cocoa butter, sugar, milk, and vanilla. The only difference is that white chocolate doesn't have any cocoa solids. Since the FDA won't let American producers label a product "chocolate" unless it has those cocoa solids, domestic white chocolate is known by a hodge-podge of different names. White chocolate scorches easily, so cook it gently. Bars and wafers usually taste better than chips. Avoid white chocolate that's made with vegetable oil instead of cocoa butter--it's cheaper but not nearly as good.
-From cook's thesaurus
...Chocolate liquor is the basis for all things chocolate. Pure chocolate liquor is very dark and bitter and has only two components--cocoa solids and cocoa butter. The solids give chocolate its characteristic dark, strong flavor, and the cocoa butter translates to a smooth mouth feel...
-From Fine Cooking
Strength is the capacity to break a chocolate bar into four pieces with your bare hands - and then eat just one of the pieces.