Baud rate is the rate at which the number of signal elements or changes to the signal occurs per second when it passes through a transmission medium. The higher a baud rate is, the faster the data is sent/received. Baud rate is commonly used when discussing electronics that use serial communication. In the serial port context, “9600 baud” means that the serial port is capable of transferring a maximum of 9600 bits per second.
Serial communication is the process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are sent as a whole, on a link with several parallel channels. Serial communication is used for all long-haul communication and most computer networks. Serial computer buses are becoming more common even at shorter distances, as improved signal integrity and transmission speeds in newer serial technologies have begun to outweigh the parallel bus’s advantage.
Some examples of serial communication include RS-3, SPI, I²C, UNI/O, -Wire and PCI Express. Morse Code Telegraphy, RS-4, RS-43, RS-485, Universal Serial Bus, FireWire, Serial Attached SCSI, Serial ATA and PCI Express are some examples of systems consisting serial communication.