A piping bag is a kitchen tool used for decorating cakes, pastries, and other baked goods. It is typically made of flexible material, such as plastic or cloth, and has a pointed end where different types of nozzles can be attached. This allows for precise control when applying frosting, cream, or other mixtures. Piping bags come in various sizes and can be disposable or reusable. They are commonly used in baking and pastry arts, making it easier to create intricate designs and patterns. Many bakers also use them for filling pastries or creating decorative elements on desserts.