High Performance Serial Bus
1394 can transfer data between a computer and its peripherals at 100, 200, or 400 Mbps, with a planed increase to 2 Gbps. Cable length is limited to 4.5 m but up to 16 cables can be daisy-chained yielding a total length of 72 m.
It can daisy-chain together up to 63 peripherals in a tree-like structure (as opposed to SCSI's linear structure). It allows peer-to-peer communication, e.g. between a scanner and a printer, without using system memory or the CPU. It is designed to support plug-and-play and hot swapping.
Sony calls it I-Link, most people call it "FireWire".