Typically, the tied product may be a less desirable one that the buyer might not purchase unless required to do so, or may prefer to get from a different seller. If the seller offering the tied products has sufficient market power in the tying product, these arrangements can violate the antitrust laws.
In general, a hub refers to a hardware device that enables multiple devices or connections to be connected to a computer. An example is a USB hub, which allows multiple USB devices to be connected to one computer, even though that computer may only have a few USB connections. The picture to the right is an example of a USB hub. Note: In the Device Manager, the root hub is your computer and the first USB hub.
The purpose of the wheel hub is to serve as the glue between the tire and the axle. Tires are attached with studs to the hub assembly. The hub assembly then fits on the axle, which connects the tire component to the rest of the car. Because the wheel hub is the bridge between the tire and the entire vehicle, if one of its parts breaks down, it creates a ripple effect. That could include problems such as impaired steering or a broken axle.