A Barrel is a Storage Container which holds 100 liters of Any Liquid, or 100 kilograms of any Dry Good. Not to be confused with the similar Providence Barrel.
Storage Containers are structures that can either store, or produces and then store, Dry Goods or Liquids. To fill or empty a Storage Containers select a Storage Vessel and right-click it on your Storage Container. Dy Good and Liquids of the same type can be combined so long as there is room in the Storage Container, but generally, Dry Goods and Liquids of differing types cannot.