A wheel is a circular component that is designed to rotate on an axle bearing. In unison with axles, wheels allow heavy objects to be moved with ease. Which facilitates movement/transportation while supported a load, or performing labor in/on machines. Wheels are also used for other purposes, such as steering wheels.
Wheels are as early as civilization itself. They were invented by small villages and tribes who needed to transport wagons and cargo long distances in scenarios where it was inefficient to carry by hand. The first wheels were largely just solid wood, or stone. However, eventually they became metal and far more easily produced.
With the rise of the Empire, tires were created, and are almost always used in tandem with wheels.