RS-232 (Recommended Standard 232) is a standard for serial communication transmission of data. It is commonly used in computers and other devices to communicate with each other and transfer data via a serial interface. The standard defines the electrical characteristics of the drivers and receivers and the data transmission timing.
RS-232 uses a single-ended signaling scheme, which means the signal is sent over a single wire, with the other wire being a ground reference. The standard defines the voltage levels for a logic "1" and "0" as well as the maximum and minimum data transmission rates. The standard also defines the pinout and connectors used to connect the devices.
RS-232 is an older standard, and it's primarily used in legacy systems. It has a limited data transfer rate, and its maximum distance is 15 meters (50 feet). However, it's still widely used in industrial, commercial, and consumer applications such as AV equipment, point-of-sale terminals, and some scientific instruments.