The purpose of FireWire is similar to that of USB: high speed data transfer for computer peripherals. High bandwidth devices, like printers and scanners, will benefit from FireWire. For whatever reason, FireWire is not as widespread as USB. FireWire cables come in two forms: 1394a (which has a transfer speed of 400 Mbps) and 1394b (which has a transfer speed of 800 Mbps).