Yes, baking powder is a leavening agent that helps cakes and other baked goods rise. When you mix baking powder into a cake batter and then expose it to heat in the oven, it produces carbon dioxide gas. This gas gets trapped in the batter, creating air pockets, and causing the cake to rise and become light and fluffy.
Baking powder is a combination of an alkaline component (usually baking soda) and an acidic component (such as cream of tartar). When the baking powder is mixed with moisture and heat, a chemical reaction occurs, releasing carbon dioxide. This process is called "double-acting" because the first reaction happens when the baking powder gets wet, and the second reaction occurs when it is exposed to heat in the oven.
The carbon dioxide bubbles expand during baking, creating the airy texture of the cake. Without baking powder or some other leavening agent, the cake would be dense and flat. So, baking powder is an essential ingredient in many cake recipes to achieve a light and fluffy texture.