RS-232 (Recommended Standard - 232) is a telecommunications standard for binary serial communications between devices. It supplies the roadmap for the way devices speak to each other using serial ports. The devices are commonly referred to as a DTE (data terminal equipment) and DCE (data communications equipment); for example, a computer and modem, respectively.

Updated designations for the RS-232 protocol have included EIA-232 (Electronic Industries Alliance) and the more current EIA/TIA-232 (Telecommunications Industry Association). These organizations have voluntarily taken on the protocol and the task of improving it.

Though RS-232 is sponsored by organizations in the United States, the most current variety of RS-232 is compatible with a standard known as ITU v.24, (International Telecommunication Union). Compliance with the international standard helps manufacturers turn out products that will work in a global marketplace.

ITU is a United Nations organization and its v.24 (pronounced vee dot twenty-four) communication standards are considered recommendations. However, in the past the slow nature of the organizations behind international standards sometimes led to varying protocols in the marketplace and the adoption of standards before they were officially "sanctioned." Today these organizations have streamlined the process of developing and disseminating new standards, making it easier for RS-232 to join in compliancy.

RS-232 sets acceptable voltage and signal levels, along with common pin designations, or configurations, for wiring serial connector ports. It also specifies protocols for the control information passed between devices, which includes such events such as indicating the beginning or end of a data stream.

Without standards like RS-232, manufacturers would have no roadmap to build compatible product lines for technology. RS-232, or serial ports, are now used almost exclusively for dial-up modems. Other devices, like mice, that used to use serial ports, now make use of newer USB and Firewire ports. As the marketplace gradually switches away from dial-up modems to DSL, cable and satellite, RS-232 will eventually become an obsolete standard.

For more information about RS-232, you can visit the Telecommunications Industry Association.