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).

General Packet Radio Service (GPRS) or general packet radio service created in the 80s is an extension of the Global System for Mobile Communications (Global System for Mobile Communications or GSM) for the transmission of data by packet switching. A similar service for mobile phones, the IS-136 system. It allows transfer rates of 56-114 kbps. These Class A devicesThey can simultaneously use GPRS and GSM services. Only Class B may be connected to one of the two services at all times. While GSM service (voice or SMS) is used, the GPRS service, which automatically restarts when the GSM service ends is suspended. Most mobile phones are of this type. Class C are alternately connected to one or another service. Switching between GSM and GPRS shouldperformed manually.

The RS232 connector is a connector type 9-pin connector is popularly called Series. It is a connector that was once widely used by various components of the PC, such as a mouse, keyboard ... but over time it has fallen into disuse and replaced by the USB connector trying to emulate the latest version number. It is currently used by robots, elevators, POS and industrial machinery.