A serial port is a communication interface that allows data to be transmitted one bit at a time over a single channel. It is commonly used to connect computers to peripheral devices, such as printers, modems, and scanners. Serial ports can be found in various forms, including RS-232 and USB, and they are essential for enabling communication between devices. Typically, serial ports use a standard connector, such as a DB9 or DB25 connector, to facilitate connections. Data is sent in a sequence of bits, making it suitable for long-distance communication. Although less common in modern devices, serial ports remain important in industrial applications and legacy systems.