Casks are large containers, typically made of wood, used for storing and aging liquids like wine, whiskey, and beer. They are often crafted from specific types of wood, such as oak, which can impart unique flavors to the liquid inside. Casks come in various sizes and shapes, with the most common being the barrel. The process of aging in casks allows the liquid to develop complex flavors and aromas over time. As the liquid interacts with the wood, it absorbs compounds that enhance its taste. Casks are also used for fermentation and transportation, making them essential in the beverage industry.