The original name for IEEE-1394 SerialPorts.
(Patented by Apple, standardized by the InstituteOfElectricalAndElectronicsEngineers).
Used on just about every digital video camera (digital camcorder) manufactured since 1995.
Used on the original AppleIpod. The latest iPods use USB2 instead, probably for the smaller chipset size and compatibility with Intel boxen.
FireWire can supply up to 45 watts of power per port, allowing moderate-consumption devices to operate without a separate power cord. (Sony iLink cameras usually delete the power part of the cable/connector system and only use a 4-pin connector. They require a separate power connector.)
FireWire ports support from 100Mbit/s to 800Mbit/s data transfer rates. Onboard or PCI ports typically support up to 400Mbit/s and use a 6 pin connector. 800Mbit/s ports use 9 pins.