DB-25
D-Sub-9 or D-Sub-25
DB-25 D-Sub-9 or D-Sub-25
DB9 is a connector, not a cable. It is most commonly used for RS-232 serial connections like an external modem.
The 232 doesn't stand or come from anywhere. It's just a reference number. RS-232 = Recommended Standard 232
RS-232
You need to get a Bluetooth RS-232 dongle, which connects to serial RS-232 port and provides bluetooth connectivity. These are similar to USB bluetooth devices to some extent, but need a power source for the electronics circuitry (as you may be aware that USB ports have 5V power supply but RS-232 standard has no option for power supply on the connector). So Serial port to Bluetooth convertors will have either an inbuilt battery or a power supply connector to feed power. Here are examples : http://www.lemosint.com/scripts/bluetooth_parani_sd.asp http://serialio.com/products/adaptors/BlueSnapXP.php - Neeraj Sharma
Recommended Standard 232
The "RS" in RS-232 stands for "Recommended Standard." RS-232 is a standard for serial communication that was introduced by the Electronic Industries Association (EIA) in the 1960s. It defines the electrical characteristics and timing of signals, as well as the physical size and pinout of connectors used for serial data exchange.
onion
The standard defines the voltage levels that represent logic levels on the line.It doesn't specify a connector. DB-9, 15, and 25 are among the popular ones,but RS-232 circuits can even be wired directly, through 3 or 4 leads, withouta connector, and without violating anything in the standard.Moreover, we should at all times remain mindful of the immortal words of the giantsupon whose shoulders we all stand:"The best thing about standards is that there are so many good ones to choose from."
it is cable used for data transmission between computers
RS-232 is used over serial ports, which are typically found on computers and various electronic devices for communication. It transmits data one bit at a time, using a standard defined by the EIA (Electronic Industries Alliance). Commonly, RS-232 ports are DB9 or DB25 connectors, though modern devices may use USB-to-serial adapters to facilitate RS-232 communication.
The RS 232 interface is one of the standards used in serial communications. It uses serial signals (as opposed to parallel) to connect computers to devices like printers and modems.