Serial port definition
A serial port is a type of interface that allows the transfer of data one bit at a time, in contrast to a parallel port which allows multiple bits to be transferred simultaneously. That’s why it’s called “serial” — the data flows in a series or line, one after the other.
It’s typically used for computers and peripheral devices (modems, mice, etc) or between computers over a network. In computer hardware, a “serial port” usually refers to RS-232 ports — older types of connections used for serial communication.
History of serial ports
The RS-232 (Recommended Standard 232) interface was introduced by the Electronic Industries Association (EIA) in the early 1960s. It became the most common type of computer serial port for many years.
During the 1980s-1990s, serial ports became a standard feature on personal computers, used for connecting peripherals like mice, modems, and printers. The introduction of the USB made traditional RS-232 serial ports less common on new computers. The USB offered faster data rates and the ability to deliver power over the same cable used for data, allowing for “plug and play” peripherals.
Today, while not commonly found on personal computers, serial ports are still used in various applications, such as industrial machinery, scientific instruments, and point-of-sale systems. In many cases, USB-to-serial converters interface modern equipment with older devices that still use serial communication.