The term "輪" (wheel) refers to a circular object that rotates around an axle. It is a fundamental invention that has greatly influenced transportation and machinery. Wheels are commonly made from materials like rubber, metal, or plastic and are used in various applications, including vehicles, bicycles, and industrial equipment. Wheels enable movement by reducing friction between surfaces. They are essential components of many machines, such as cars, trains, and bicycles. The invention of the wheel is considered one of the key advancements in human history, facilitating trade, travel, and the development of technology.