"Useful" refers to something that has practical value or can help achieve a specific goal. For example, a tool like a hammer is useful for driving nails into wood, making it easier to build furniture or fix things around the house. Similarly, a smartphone is useful for communication, allowing people to connect with others instantly, access information, and manage their daily tasks. In everyday life, being useful can also apply to skills or knowledge. For instance, learning how to cook is useful because it enables individuals to prepare healthy meals at home, saving money and promoting better nutrition. Overall, usefulness enhances our ability to navigate challenges and improve our quality of life.