Firewire - Firewire is a high-speed data transfer interface promulgated by Apple and used on early iPods. Because Firewire offers high-speed transfers, it is used in applications where large amounts of data are moved, such as video.
Firewire competes with USB and though Firewire is faster, USB is more widely used.
Early iPods used Firewire for syncing. When Windows compatible iPods were released, they used USB to sync (USB is more common on PCs than Firewire) and Firewire for battery charging.
Firewire connections are achieved on computers by plugging Firewire cables into Firewire ports on computers and peripherals. Firewire is denoted with the icon shown on the Wikipedia page linked to below.
There have been three different Firewire specs - 400, 800, and 1394b.
Maximum Connection Speed
786 Mbits/second using Firewire 800
Used In iPods
Used in all iPods prior to fifth-generation.