system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is the difference between baking powder and baking soda?
gpt
The top comment is correct, but in case it's too technical:

Both baking powder and baking soda are used to create a rise in baked goods. The chemical reaction they cause makes bubbles that puff up the dough. Baking soda needs an acid added to the dough to make that reaction happen (like your grade school volcano). Baking powder is baking soda plus an acid that activates when it gets wet. Which one you use depends on the recipe (is there an acid?) and how much rise you want (baking soda is stronger but  too much of either powder can affect tastes so sometimes you want a big rise and you use both).