Like a USB port, FireWire is an external connector that can be used to connect a secondary device with a personal computer at a high data rate. It is commonly used for connecting various typical devices such as camcorders, external hard drives, digital audio/video, home entertainment applications, printers and others with a computer.
The IEEE 1394 is a serial bus interface which is used as a standard for high-speed data transfer rate connections and is also used for isochronous data transfer in real time. This interface was developed and introduced by Apple in the end of 1980s and beginning of 1990s. Apple named it FireWire.
In general, FireWire offers a single-and-socket type of connection that can be used to connect 63 devices at a very high data rate of 400 Megabits per second (Mbps). A later standard, IEEE 1394b increased the data rate to 800 megabits per second.
Firewire was very popular for a time but began to lose its market share after Apple removed it as a standard port on the Macbook back in 2012. Still there are many accessories for video and audio that use Firewire. Apple sells adaptors to convert from Firewire to the new Thunderbolt format so these devices can still be used.
Firewire is particularly useful for low scale live streaming applications where typically it will be used to connect a video camera to a PC or Mac where it’s output can be encoded and transmitted onwards via the internet to the PlanetStream network. This provides a low cost live stream solution for small events such as weddings, sport, music and theatre.
Although a slightly aging technology it can still produce excellent results and there is a lot of high quality second hand equipment around that makes use of it.