I might not be quite right with that one

In which of these cases would you be most likely to use a cable with a DB-9 connector?

A) Connecting an external storage device

B) Attaching a mouse or keyboard to a desktop computer

C) Configuring a router

D) Connecting a POTS line to a modem

E) Attaching a video camera to a computer

F) When a DB-8 cable is too short

The answer: C) Configuring a router

DB-9 cables are commonly used for serial connections, and serial cables are commonly used for connectivity to infrastructure equipment for setup and configuration. You may also see the DB-9 interface called a DE-9 interface.

The D refers to the style of the interface (it’s shaped a bit like a D), the second letter is the size, and the number refers to the number of pins inside of the connector. The number does not refer to the length of the cable.

Want to know more? Watch “Device Connectors and Cables.”

There are many different types of devices that can connect to your computer, and many of them use completely different connectors. In this video, you’ll learn about the cables and connectors used for hard drives, USB devices, FireWire components, parallel links, serial connections, network links, and much more.