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 conjunction with cake decorating techniques and are essential for creating intricate designs, such as roses or borders. Proper use of a piping bag can enhance the presentation of desserts significantly.