Baking powder is a leavening agent used in baking to promote the rising of dough or batter. It typically consists of a combination of an acid (usually cream of tartar), a base (usually baking soda), and a starch or filler (such as cornstarch). The acid and base components are carefully balanced to react when exposed to moisture and heat, releasing carbon dioxide gas. This gas expands during baking, causing the mixture to rise and resulting in a light and fluffy texture in the final baked goods. Aluminum-based compounds may also be included in some baking powders to enhance their leavening action.