When creating or editing a recipe, you can add the shopping items you need to get and to check (pantry items) for that recipe, so then all you have to do is add the recipe name to your shopping list or to you plan and the shopping list will automatically pull all the items into the shopping list.
Shopping items can be different from ingredients, to make it easier to know what to buy in the store. For example recipes are often measured in cups or teaspoons, but you won’t see two cups of carrots in the store. With your shopping list you can define the items to look for in the store.