

For example if a microcontroller 1 is transferring data to another microcontroller 2 in serial form then TXD pin of microcontroller 1 will be connected to RXD pin of microcontroller 2 and data is transferred from microcontroller 1 to microcontroller 2 in bit by bit manner over a single wire. On the other hand in serial communication, data is transferred in bit by bit manner over a single wire. In parallel communication, data is transferred over more than one wire for example if 8 wires of one microcontroller are connected to any other peripheral device or another microcontroller then at a particular time 8 data bits are transferred. Microcontrollers can communicate data in either parallel form or serial form.
