A barrel is a cylindrical container traditionally made of wood, metal, or plastic. It is commonly used for storing liquids such as wine, beer, and oil. Barrels are designed to hold a specific volume and often have a curved shape, which helps in the aging process of beverages like whiskey. Barrels can vary in size, with some holding just a few liters while others can contain hundreds of liters. The construction of a barrel typically involves staves, which are the wooden planks that form the sides, and metal hoops that hold the staves together. This design allows for easy transportation and storage.