USB hub

USB hubs such as this one are common.

USB is an international standard of technology for connecting peripherals to computers and other devices that support it. An interface where a USB device can be connected is called a port. A USB hub is a special device which allows adding more USB ports. The additional ports share one USB connection to the computer; for this reason, each of them cannot carry as much data as a direct USB connection can.

A hub may be bus-powered, which means it gets all its electrical power from the computer. This makes simple wiring, but it cannot give full power to its peripherals. A self powered hub has its own power cord, and can give full power to peripherals that need it.

There are different versions of the USB standard; main difference between the version is the maximum speed that is supported. The USB standard also defines different types of USB plugs.

A USB hub is a normal USB device, which was built for a given version of the standard. Certain models may support different versions of USB, while others may not. As an example: USB 3.0 can transfer payload data at up to 4 GBits per second. USB 2.0 is limited to a transfer rate of 280 MBits per second. Connecting an USB 3.0 device to the computer using an USB 2.0 hub will limit the transfer rate to that of USB 2.0.