A parallel port is a type of interface used to connect peripherals, such as printers, to a computer. It transmits multiple bits of data simultaneously, allowing for faster communication compared to serial ports, which send data one bit at a time. Parallel ports were commonly used in the past for devices like dot matrix printers and scanners. Typically, a parallel port has a 25-pin connector, known as a DB-25 connector. While they have largely been replaced by faster interfaces like USB and Ethernet, parallel ports are still found in some legacy systems and specialized equipment, making them relevant in certain contexts today.