The centerbore of a wheel is the machined opening in the center of the wheel that centers the wheel properly on a vehicle. It is important for a wheel to be "Hub Centric" because it will reduce the chance of vibration.
Vehicle Hub Centric Wheels - which mean that the hub bore is machined out exactly to the size of the exact vehicle bore.
Multi-Application Wheels - which means that the wheels are machined out to a larger bore so they will fit a variety of vehicles. In this application you would use a centering ring to reduce the bore to match the vehicle. (see picture below) At Town Fair Tire we include a set of centering rings at no charge with the purchase of Multi-Application alloy wheels to ensure a smooth factory ride.
Lug Centric Wheels - which means the wheel is designed to use the lug nuts to center the wheel and not the hub. The most common example of a Lug Centric Wheel is a steel wheel.