USB (Universal Serial Bus).
Universal Serial Bus (USB) is a royalty-free bus specification developed by leading manufacturers in the PC and telephony industries to support plug-and-play peripheral connections. USB offers increased bandwidth, isochronous and asynchronous data transfer, and lower cost than conventional input/output ports. Designed to consolidate the cable clutter associated with multiple peripherals and ports, USB supports all types of computer- and telephone-related devices.
USB detects and configures the new devices instantly
Before the arrival of Universal Serial Bus (USB), adding peripherals required skill. You had to open your computer to install a card, set DIP switches, and make IRQ settings. Now you can connect digital joysticks, scanners, speakers, cameras, or PC telephones in seconds. Instead of opening up your CPU to insert new boards, you make all the connections outside the case to the USB port. USB detects and configures the new devices instantly.