Serial Port

[technoguy]

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). Throughout most of the history of personal computers, data transfer through serial ports connected the computer to devices such as terminals or modems. Mice, keyboards, and other peripheral devices also connected in this way.

[vipl]

Serial Ports provide a standard connector and protocol to let you attach devices, such as modems, to your computer. Most computers have at most two serial ports, and they are very slow in most cases. The Universal Serial Bus (USB) gives you a single, standardized, easy-to-use way to connect up to 127 devices to a computer.