Firewire also known as IEEE 1394, is a high-bandwidth interface for computers, peripherals, and consumer electronics products.
Firewire was originally developed by Apple Computers as a high speed serial bus, but they were ahead of their time as many believed the technology to be too fast and that USB alternatives would be easier and cheaper to integrate into the market.
Apple did however include some ports in Macs for a number of years, and now the format has developed enormously and is growing rapidly especially with digital editing users who can benefit the most from the technology.
Its main advantage is similar to USB it is hot plugable and can also be used to connect many devices together (63 devices per port) but its primary use is that it allows high-bandwidth transfer mostly used at present with digital cameras, and camcorders.
We are told that transfers of around 400Mbps can be achieved, this is more than 30 times the bandwidth of USB. And as the USB 2.0 and Firewire technology develops to doubt these speeds will be increased substantially.
Its connections are similar to USB and the ones that have been used on Nintendo Gameboys. On some cards you get two or more IEEE 1394 ports as well as two USB ports so once this is installed you can have the best of both worlds. You can run web cams / mice off the USB and the higher transfer devices like cameras, cd writers etc can run off the IEEE 1394 ports
FireWire's future looks set to grow and even when the 'rival' of USB 2.0 is fully complete, Firewire2 will most likely be ready to roll straight over USB 2.0 with even faster transfer and benefits.
Although slightly expensive at present if you are using Multimedia / Editing then you'll be well advised to spend the extra, cards are around the £50 mark for internal PCI connection adapters which include just IEEE 1394 connections.