Most of the peripherals currently available on the market connect to the personal computer through USB ports. Up to 14 or more types of electronic devices, each with different functions, can be bought today from just about anywhere, while a typical computer only has two to four standard USB sockets. Thus, if you want to use more than four peripherals at the same time, you will quickly realize that your computer is out of ports.

Since the USB standard is able to support up to 127 devices at the same time, the problem can be easily solved with the help of a USB hub, which is a peripheral connecting to the PC through a single USB socket and able to emulate additional new ports. In the end, from a single USB connection on your computer and with the help of several USB hubs connected with each other, one could create a few couple of tens of new USB ports.

There are two types of USB hubs that can be used, according to the type of peripherals connecting to them: powered and unpowered.

Unpowered USB hubs are generally used for devices that have their own power supplies, such as printers or scanners, but can also be used to connect a small number of low-power peripherals that do not have separate power supplies and receive energy from the motherboard, like mice for example. The hub itself draws electric current from your computer to function properly.

However, if you want to connect multiple low-power devices through the hub, the electric current provided by the computer (approximately 5 volts at 500 milliamps) may not be enough to supply energy for both the peripherals and the hub. In this case, powered USB hubs are preferable. They usually come with their own transformer and do not draw any energy at all from the power supply of the PC.

Considering that the USB 1.0 standard allows a maximum information transfer rate of 12 megabits per second and the USB 2.0 standard 480 megabits per second, and the fact that typical devices only require about 6 megabits per second, one could practically connect up to 80 devices at the same time to a personal computer with the help of several USB hubs.