Barrels are cylindrical containers typically made of wood, metal, or plastic. They are used for storing and transporting liquids, such as water, oil, or wine. The design of a barrel allows for easy rolling and stacking, making it efficient for storage and movement. In the context of brewing and winemaking, barrels play a crucial role in the aging process. Wooden barrels, particularly those made from oak, can impart unique flavors to the liquid inside. The porous nature of wood allows for a small amount of oxygen to interact with the liquid, enhancing its taste and aroma over time.