A common standard for serial communications is RS232 Summary Parallel transmission sends each bit using a separate wire. In addition, extra wires are needed to transfer the data between the sender and receiver. These handshake signals allow the data to be transferred in the correct sequence. Computers often send data in parallel form because it is fast. An example of a parallel format is the Centronics parallel interface.
Serial data is slower than parallel, but suited to long distances.
An example of a serial format is RS232. Copyright B Brown. All rights reserved.