What Are The Function Keys For?

Which keys are the function keys?
Function keys
The function keys are the keys marked F1 to F10 (or F1 to F12, depending on the keyboard) on the top row of the keyboard. Typically, each of these keys will perform two different functions:

  • they will perform the task assigned to the number of the key (eg F2 may be assigned the “find” command)
  • they will perform the task indicated by an icon on the key itself (often in a different colour from the rest of the keys). On the keyboard illustrated here, the F2 key will indicate the charge level of the battery.

How does the key know which of these two functions to perform?

  • if the key is pressed on its own then the specific function key will be actioned (eg F2 = find)
  • if the key marked Fn is depressed and then (with the Fn key still depressed) the function key is pressed, then the alternative use of that key is actioned (eg display battery state)

So, what are the “functions” that are carried out when a specific function key is pressed on its own?

It depends on the context. More specifically, it depends upon how the current program has been set up to use the function keys. The current program is the one that “has the focus” – ie the one that is currently reacting to your key presses and your mouse movements and clicks.

So, if the current program has been set up to use the F5 key as a “find” instruction, then pressing F5 will execute a “find” command. In Word 2007, for instance, pressing the F5 key executes a “find” command in exactly the same way as pressing the key combination of Ctrl F (pressing the “f” key while the Ctrl key is depressed) or finding and clicking the “find” instruction on the “ribbon” of commands at the top of the screen.

The whole point of the function keys is that they can perform different functions depending upon the program that is using them. Over time, some uses of the function keys have become more-or-less standardised. For instance, the F1 key almost always invokes the “Help” system for the current program. However, a bit of experimentation is needed to find out how a particular program has been set up to use the function keys (or consult the help system for the specific program by pressing F1).

If this is a bit confusing then there is no need to worry about function keys at all. I think it’s safe to say that there is always an alternative way of carrying out whatever the function keys do.

What do the symbols on the function keys mean that denote the alternative use of the function keys?

Sorry about this, but, once again, it depends. This time it depends on the particular keyboard. The best way to find out is probably to experiment, but it is strongly advised that you do not have any programs loaded when you do this as you may get unexpected results and you wouldn’t want to harm a document.

Some of the common icons and their uses are:

  • a moon – puts the machine into sleep mode (standby)
  • two different versions of suns – increase and decrease the screen brightness
  • loudspeaker – turn the sound on
  • loudspeaker crossed out – turn the sound off
  • various icons that denote increasing and decreasing the volume
  • computer monitor – switch the output to/from an external monitor

Will I break anything if I play with these keys?

It isn’t always completely clear what a function key does but if you are not sure if your experimenting has changed something then you can always re-boot the machine. This will return all the keys to the state they had previously been in.

One particular hint that is appropriate here is that laptops often have a key combination (usually the Fn key plus a function key) that turns the WiFi connection on and off. There doesn’t seem to be a universally agreed symbol (icon) for this but if your WiFi stops working after playing with these keys then this is worth investigating. The same key combination that turned the WiFi off will turn it back on again. There may or may not be an LED light somewhere on your laptop indicating that the WiFi is on or off. Similarly, some laptops have a slider switch for turning the WiFi on and off, so it’s worth checking this out as well if your WiFi suddenly disappears. If in doubt, re-boot and everything should go back to how it was before you starting investigating.

In a future blog I will do a roundup of the other keys that are not immediately obvious in their function and use.