A Serial port was once the staple connection to a computer. However today you may not even find one on your computer. The term "serial port" usually identifies hardware more or less compliant to the RS-232 standard. It is intended to interface with a modem or with a similar communication device. Often a terminal screen was connected to the computer via a serial port.
The full standard for RS-232 requires a 25 pin connector but many computers used the connector shown on the right that had only 9 pins. The "D" shape was common to all of the connectors. The image also shows the serial icon above the connector itself.
 Alternate Solutions
- A Serial port adapter can be obtained for a USB port.
- Serial Port over network can provide a solution to another device with a real serial port.