A wheel is a round object that can rotate around a central point. It is one of the most important inventions in human history, allowing for easier movement of heavy loads. Wheels are commonly found on vehicles like cars, bicycles, and trains, making transportation faster and more efficient. The basic design of a wheel includes a circular rim and a hub in the center. When a wheel turns, it reduces friction with the ground, enabling smooth travel. Wheels are also used in various machines, such as gears and pulleys, showcasing their versatility in both everyday life and industrial applications.