A serial port is a computer interface used to communicate with external devices such as modems, mice, and some digital cameras. Data is transmitted one bit at a time, making it slower than modern interfaces like USB or FireWire.
While serial ports are rarely used today for transferring large files, they were once standard for connecting peripheral devices and remain relevant for certain legacy equipment. Photographers and technicians working with older digital or imaging devices may still encounter serial ports, making understanding their function important for maintaining compatibility and workflow with vintage hardware.