USB Hub

A USB hub is a piece of hardware that allows for a single USB port to be expanded into several. This allows more ports to be used for different connected devices. For example, on a computer there might be four USB slots, but within the actual computer, there might only be a single upstream port. This means that the four downstream ports are connected to one port that leads within the computer. The USB hub allows for the four separate ports to connect together while keeping their autonomy and run into the computer via the upstream port.

A USB hub can typically be found within keyboards, monitors and printers. For the most part, if there is more than one downstream port–the port that connects an external component to the computer–chances are, there is a USB hub. However, USB hubs can also be external. For example, a USB hub would be connected to one of the USB drives on the computer. Then, four separate things would connect to that external drive. This way, a lot more could be connected to the computer rather than the typical three or four drives that most computers come with.

One of the problems with a USB hub is that, as you start to connect more things to it, they don't work as effectively. For example, on a horizontal array of sockets, often times only two out of four ports are usable. While this all depends on the plug width, the horizontal sockets get blocked by adjacent ports, so they are less effective.

To combat this, developers have released port arrays that have the different ports perpendicular from others. So, there might be a port across from another port, but then there are ports perpendicular as well. This creates a "star" shape and this has far fewer blockage problems because there is more space for each individual port. Another type of hub that is used is known as the Octopus hub. With this, there is a socket at the end of a short cable. This, too, avoids the problem of space and ports not working.

The one other thing that a USB hub can do is act as a connector. USB cables are limited to 5m long. However, if one USB cable is plugged into a hub, another 5m cable could be connected to the other side of the hub and therefore, the USB has been extended to 10m. This allows for things to reach farther. The USB hub, in other words, acts like an extension cord or as a connector between two cords.