The main component of baking soda powder is sodium bicarbonate, also known as baking soda, which is a single-component substance. Baking powder is a compound puffing agent composed of ammonium alum, sodium bicarbonate, starch, calcium carbonate and other substances. Therefore, baking powder is a kind of baking powder containing baking soda, but it is not baking soda.

Baking powder and baking soda are commonly used as baking powder, but they are different. Baking powder is mainly used for the rapid production of bread, cakes and biscuits, while baking soda is mainly used for making biscuits. It can be mixed with the above two kinds to adjust the pH of dough and achieve the best eating effect.