White chocolate is prepared from cocoa butter and commonly adds sugar, although it still comes from the cacao plant. In contrast, both dark and milk chocolate retain the cacao nib after processing and cocoa butter and additional sugar. Tempering refers to heating chocolate and then allowing it to cool somewhat before using it in a recipe.
When done correctly, it gives the chocolate a lovely sheen and gratifying snap, typical of gourmet and artisanal delicacies. So, we know a bit of white chocolate and a bit of tempering.