Universal Serial Bus (USB) is a serial bus standard to interface devices. USB was designed to allow peripherals to be connected using a single standardized interface socket and to improve plug-and-play capabilities by allowing devices to be connected and disconnected without rebooting the computer (hot swapping). Other convenient features include providing power to low-consumption devices without the need for an external power supply and allowing many devices to be used without requiring manufacturer specific, individual device drivers to be installed.

USB is intended to help retire all legacy varieties of serial and parallel ports. USB can connect computer peripherals such as mouse devices, keyboards, PDAs, gamepads and joysticks, scanners, digital cameras, printers, personal media players, and flash drives. For many of those devices USB has become the standard connection method. USB is also used extensively to connect non-networked printers; USB simplifies connecting several printers to one computer. The large volume of USB memory devices and their ease of use has created a security concern that is often overlooked. USB lock software can lock out memory devices and still allow other USB peripherals to function. The USB was originally designed for personal computers, but it has become commonplace on other devices such as PDAs and video game consoles. In 2004, there were about 1 billion USB devices in the world. *** info take from wikipedia.com