The USB is a standard for peripheral devices. It began development in 1994 by a group of seven companies. USB was intended to make it fundamentally easier to connect external devices to PCs by replacing the multitude of connectors at the back of PCs, addressing the usability issues of existing interfaces, and simplifying software configuration of all devices connected to USB, as well as permitting greater bandwidths for external devices. The first silicon for USB was made by Intel in 1995.
The USB 1.0 specification was introduced in January 1996. The original USB 1.0 specification had a data transfer rate of 1.5 Mbit/s. The first widely used version of USB was 1.1, which was released in September 1998. It allowed for a 12 Mbit/s data rate for higher-speed devices such as disk drives, and a lower 1.5 Mbit/s rate for low bandwidth devices such as joysticks
The USB 2.0 specification was released in April 2000 and was standardized by the USB-IF at the end of 2001. HP Intel, Lucent technologies (now Alcatel-Lucent), NEC and Philips jointly led the initiative to develop a higher data transfer rate, with the resulting specification achieving 480 Mbit/s, a fortyfold increase over 12 Mbit/s for the original USB 1.1.
The USB 3.0 Specification was published in 12 November 2008. Its main goals were to increase data transfer rate (up to 5Gbps), decrease power consumption, increase power output and be backwards compatible with USB 2.0. USB 3.0 includes a new, higher speed bus called SuperSpeed in parallel with the USB 2.0 bus. For this reason, the new version is also called SuperSpeed. The first USB 3.0 equipped devices were presented in January 2010.