USB (Universal Serial Bus) is a plug-and-play interface between a computer and add-on devices, such as media players, keyboards, telephones, digital cameras, scanners, flash drives, joysticks and printers.
USB supports hot-swapping, which means that a new device can be added to your computer without having to add an adapter card or even having to turn the computer off. The USB peripheral bus standard was developed by Compaq, IBM, DEC, Intel, Microsoft, NEC, and Northern Telecom. The technology is available without charge for all computer and device vendors.
Since 1996, Windows operating systems have been equipped with USB drivers or special software designed to work with specific input/output (I/O) device types. Most new computers and peripheral devices are equipped with USB.
In November 2008, the USB Implementers Forum (USB IF) released specifications for USB 3.0, officially known as SuperSpeed USB. According to Forum president Jeff Ravencraft, a USB 3.0-capable flash drive can transfer a gigabyte of data (the equivalent of two full-length movies) to a host device in 3.3 seconds. In contrast, it takes a USB 2.0-based device 33 seconds to transfer that amount of data.
USB 3.0-capable devices are expected to be available in 2010.
See also IEEE 1394.