Parallel communication modern computers. Before the development of high-speed serial technologies, the choice of parallel links over serial links was driven by these factors: The decreasing cost and better performance of integrated circuits has led to serial links being used in favor of parallel links; for example, IEEE 1284 printer ports vs. USB, Parallel ATA vs. Serial ATA, and FireWire or Thunderbolt are now the most common connectors for transferring data from AV(audiovisual) devices such as digital cameras or professional-grade scanners that used to require purchasing a SCSI HBA years ago. One huge advantage of having fewer wires/pins in a serial cable
Serial port COM1, COM2..etc. Ports numbered greater than COM9 should be referred to using the \\.\COM10 syntax. The RS-232 standard is used by many specialized and custom-built devices. This list includes some of the more common devices that are connected to the serial port on a PC. Some of these such as modems and serial mice are falling into disuse while others are readily available. Serial ports are very common on most types of microcontroller, where they can be used to communicate with a PC or other serial devices. Since the control signals for a serial port can be easily turned on