Computer ports

In computing, a serial port is a serial communication physical interface through which information transfers in or out one bit at a time (contrast parallel port).[1] Throughout most of the history of personal computers, data transfer through serial ports connected the computer to devices such as terminals and various peripherals.

While such interfaces as Ethernet, FireWire, and USB all send data as a serial stream, the term "serial port" usually identifies hardware more or less compliant to the RS-232 standard, intended to interface with a modem or with a similar communication device.

For its use to connect peripheral devices the serial port has largely been replaced by USB and Firewire. For networking, it has been replaced by Ethernet. For console use with terminals (and then graphics) it was replaced long ago by MDA and then VGA. While nearly every server has a serial port connector, most non-poweruser workstations and laptops do not have a outwardly wired one as it is a legacy port, and superseded for most uses. Serial ports are commonly still used in legacy applications such as industrial automation systems, scientific analysis, shop till systems and some industrial and consumer products. Network equipment (such as routers and switches) often use serial console for configuration. Serial ports are still used in these areas as they are simple, cheap and their console functions (RS-232) are highly standardized and widespread.

The vast majority of computer systems have a serial port, however it must usually be wired manually and sometimes there are no pins in the manufactured version.