Functional keys appeared with the release of IBM PC / XT personal computers in 1983 and served for quick calling of frequently used functions.
Over the past thirty-odd years their appointment remains the same.
The actions performed by pressing each of the twelve function buttons may differ depending on the operating system or even the application, but there are universal purposes.
On the first keyboard PC / XT, where there were functional keys, there were only ten, and they were placed on the left in two rows.
F1 is the help call key. Works almost everywhere - from old text to modern applications, in the Windows family, in many GNU / Linux distributions. An exception is, except that Mac OS.
F2. Its common function is editing. In Windows Explorer, pressing F2 renames the file, in some file managers it opens the file for editing. In addition, the F2 key serves to open BIOS settings along with Del.
F3. The main purpose is to call the search, whether it's searching in Explorer, on a web page in the browser or in an open document. Similarly, Ctrl + F works.
F4 - varies from program to program. In some browsers and Windows Explorer, you move the cursor to the address bar with a simultaneous display of the history.
F5. A universal purpose is the refresh function. Updates the contents of browsers, management consoles, explorer, file managers and many other programs.
A useful combination when working with the browser is Ctrl + F5. It allows you to refresh the page without using the cache.
F6 does not have a standard function. In browsers, the action is similar to F4, but the history is not displayed. It is often used to switch between controls like a Tab key.
F7, F8, F9 - the assignment depends on the specific program or OS. When Windows starts, pressing F8 displays a menu with boot options, and F9 activates system recovery.
F10 - call the menu, not a single, but quite frequent assignment, and the combination Shift + F10 brings up a context menu, similar to the right mouse button.
F11 - the most common assignment is switching between windowed and full-screen modes.
F12 on Mac OS calls the Dashboard widget by default. Also, this OS allows you to use the F9, F10, F11 keys for Expose - the technology of window management.
Functional keys are often used inCombinations with the so-called modifier keys - Shift, Ctrl and Alt. For example, Alt + F4 will close the application, and Ctrl + F4 its separate element - tab, window, file.
In addition, on laptops you can find a buttonFn, in combination with a functional keyboard, it can control the sound, brightness or contrast of the screen, power the radio modules Wi-Fi and Bluetooth, disable the touchpad and many others. Specific combinations depend on the manufacturer and model of the laptop.