Answer
Baking Powder:
Its includes an acid and a base, it is used in recipes that have other relatively neutral ingredients, like milk. It is commonly found in cake and muffin recipes.
Baking soda:
It is more common in recipes that have acidic ingredients that it can react to, such as yogurt, citrus juice, or buttermilk. Baking soda is used for foods like cookies and quick breads, such as banana bread.