RS-232 (Recommended Standard 232, also known as EIA/TIA RS-232C) is an interface that designates a standard for the exchange of a series of binary data between a DTE (Data Terminal Equipment) and DCE (Data Communication Equipment , Data Communication Equipment), although there are others in which the RS-232 interface is also used. An equivalent definition published by the ITU is called V.24. The RS-232 is a connectorDB-25 type (25-pin), although it is normal to find the version of 9-pin (DE-9, or popularly also called DB-9), cheaper and even extended to certain types of peripherals (such as serial mouse PC).

The mini-DIN connector designates a family of circular connectors, each with a diameter of 9.5 mm and a varied number of pins inside. Although initially designed as mere electrical connectors, they are very popular in electronics and computers, having succeeded the larger DIN connector. Both are standards of Deutsches Institut für Normung, the German standardization body.