Updated: 09/12/2023 by Computer Hope
Illustrated awards podium for first, second, and third place.

In general, secondary refers to the second in an order. For example, with a computer, a secondary storage device is a hard drive. All programs run from the primary storage (memory), and the data is stored in the secondary storage.


If you're looking for information about the number two key, see our two page.

What is a keyboard key secondary function?

When describing a keyboard key, a secondary function describes a function accessed by pressing an additional key. For example, on a Dell laptop, the F3 may also have the function to mute the sound. Pressing the Fn and F3 activates that second function and mutes the sound. However, pressing the key alone does the function key action.

Secondary jumper setting

As shown below, a secondary jumper setting is found on a hard drive or CD-ROM (compact disc read-only memory) and adjusted using jumpers. The secondary setting allows two devices to be attached to a single IDE/ATAPI connection.

Jumpers on back of IDE hard disk drive


With early hard drives, this setting was called "slave." However, because "slave" is offensive, it's better to refer to this drive as "primary" or "device0."

Other examples of secondary with computers

Hard drive, Number, Primary, Two