Short for Function, Fn is a key found on most laptop keyboard and most latest desktop keyboard. The Fn key performs extraordinary function, for example, altering the screen's splendor brightness and increasing and decreasing the computer speaker volume.
Just you can see in the picture above, this keyboard has an Function (Fn key) with a blue fn and green Fn Keys with symbols of the same color indicate that their secondary function will be activated by pressing that key with the Fn key. E.g, by pressing and holding down the Fn key, along with the up arrow or down arrows, will be adjusting the computer screen brightness.
On a laptop keyboard computers, the Fn key is mostly be found on the bottom-left side of the keyboard, that next to the Ctrl key which is control key.
But Not all Chromebook have an Fn key. For those that do have an Fn key, it is often located near the spacebar key.
On full-sized Apple desktop computer keyboards, the Fn key is found to the right of the Delete key. It is usually written as fn.
Most olden desktop computers keyboards don't have an Fn key. For those desktop computer keyboards that do have an Fn key, it is often located around the spacebar.
With most computer keyboards, the Fn key is used like other modifier keys (e.g., the Shift key). By pressing and holding the Fn key in with another key that has an Fn function, that function is performed.
For example, consider the photo above of the F12 key on an Apple keyboard. This key also has an icon of a speaker, making the F12 key an audio volume control key. If you press this key, it adjusts the volume of your speakers. However, if you hold down the Fn key when you press the F12 key, it's interpreted as the F12 key. Holding down Fn changes from the default key action to the alternate. You can configure which action is the default, and which action is the alternate, in the keyboard section of your System Settings.
On desktop computer keyboards with an Fn key that lights up when enabled, you need to make sure the key is enabled (illuminated) before pressing the corresponding function key. Once the key is illuminated, it no longer needs to be pressed, and each function is performed until the Fn key is disabled.
Not all Fn keys are color-coded. For computers with a white or black Fn key, it still performs the same function and can be pressed in combination with other keys that have pictures on them. For example, pressing the Fn key and a key with a sun on it should adjust the brightness. Pressing the Fn key and a key with a crescent moon should put the computer to sleep.
The functions available to the Fn key all depend on the computer manufacturer and the type of keyboard. Below is a list of some of the common functions this key can be used to perform.
If your computer did not include a keyboard with the Fn key, it has no alternate functions on those keys. You may consider upgrading your keyboard to a different model, such as a multimedia keyboard.
Drop your comment if you know another function of that key.