What is baking powder used for?

Baking powder is useful for mixing into many types of batter and dough as leavening. It already contains an acid, so it does not need additional acid in the batter, as baking soda needs. Some baked good that use baking powder as leavening are Quick Breads, Cookies, Biscuits, Cornbread, Muffins, Pancakes and Waffles.