A cask is a large container, typically made of wood or metal, used for storing liquids, especially alcoholic beverages like wine and whiskey. Casks are designed to allow for aging, which can enhance the flavor and quality of the liquid inside. They come in various sizes and shapes, with the most common being the barrel shape. Casks are often made from specific types of wood, such as oak, which can impart unique flavors to the contents. The process of aging in a cask can also involve interactions with the wood, leading to changes in color, aroma, and taste, making casks essential in the production of many spirits.