USB 3.0, also known as SuperSpeed USB, provides the bandwidth to transfer data at close to ten times the speed of USB 2.0 and is now becoming available in the market. The theoretical improvement in data transfer speeds provided by USB 3.0 is dramatic.
USB 3.0 is backward compatibility with USB 2.0 although you need a new cable and new host adapter or one of the new motherboards that support USB 3.0 to achieve USB 3.0 speeds, but you can still use the device on a USB 2.0 port and achieve typical USB 2.0 performance.