Cacao vs Cocoa: Theobroma Cacao is the scientific name of the cacao tree. Cacao can refer to the tree or the seeds/beans of the tree. Once the beans have been processed (fermented, dried, and/or roasted) they are no longer viable seeds and are then called cocoa beans.
Chocolate Maker vs Chocolatier: Chocolate makers create chocolate out of the individual components. They focus on cocoa origins, roasting profiles, percentages, and other aspects of flavor and quality. Chocolatiers take pre-made chocolate and make wonderful creations that combine beauty and flavor; things like bonbons, truffles, etc.
Chocolate Liquor vs Chocolate Liqueur: Chocolate liquor does not contain alcohol and is the result of crushing cocoa solids and butter into a liquid/paste. Chocolate liqueur is an alcoholic drink made of liquor and added chocolate.
Percent Cocoa: The percent of a chocolate bar tells you how much cocoa is in the product in relation to all other ingredients. This includes cocoa butter and cocoa solids.
Black Cocoa: Black Cocoa aka Dutched Cocoa has been treated with a base/alkali. This darkens it and reduces the acidity. Oreo cookies are made using black cocoa.