The Universal Serial Bus is technology that allows a person to connect an electronic device to a computer. It is a fast serial bus.It is mostly used on personal computers. USB is also used on other devices, like the PlayStation 3, PlayStation 4, the Xbox 360, and others. USB connects different devices using a standard interface.Most people use USB for computer mice, keyboards, scanners, printers, digital cameras, and USB flash drives. There are over six billion USB devices around the world.
Source: Wikipedia :P