Oat names describe how the grain has been processed. Rolled oats are flattened, quick oats are usually thinner or smaller, and steel-cut oats remain little pieces of the groat.
That affects cooking time and texture. A recipe designed around rolled oats may turn softer with quick oats or remain unpleasantly hard with uncooked steel-cut oats. Follow the packet when making porridge and the recipe when baking.
If you need gluten-free food, choose appropriately labeled oats and consider the eater's specific requirements; an ordinary oat packet is not automatically suitable. Store the oats dry and sealed. In a warm kitchen, buy an amount you can use comfortably rather than leaving a large opened sack beside the oven for months.