RS-232 - Wikipedia
https://en.wikipedia.org/wiki/RS-232
In telecommunications, RS-232, Recommended Standard 232 is a standard originally introduced in 1960 for serial communication transmission of data.
What is RS232 Protocol and How it Works? - Codrey Electronics
https://www.codrey.com/embedded-systems/rs232-serial-communication/
Historically, RS232 Communication protocol is an old serial communication protocol developed by EIA (Electronics Industry Alliance)/TIA (Telecommunications Industry Association)-232 in the year 1962.
What is RS232 and What is it Used for? | RealPars
https://realpars.com/rs232/
Today you will learn what RS232 is and what it is used for. It is a phrase you may hear fairly regularly in industry, especially by the older guys. Hopefully this video will clear some things up for you.
RS232 Protocol: Introduction To The Standard And The Interface.
https://www.omega.com/en-us/resources/rs232-serial-communication
RS-232 is widely used for connections between data acquisition devices and computer systems. RS-232 devices are defined as either DTE (usually a computer) or DCE (usually an interface device).