USB Hubs: A USB hub is a quick and easy way to add additional USB ports to your computer. A USB hub will plug into a USB port on your system and split it into multiple USB ports for you to use. There are two basic types of USB hubs: powered USB hubs and unpowered USB hubs. A powered USB 2.0 hub will come with an AC adapter that plugs into the wall. This lets you use any USB device on it. An unpowered (or bus powered) USB 2.0 hub can only be used on devices that are low power or externally powered (ie- devices that have their own power cord).