F1, F2, F3, F4, F5, F6, F7, F8, F9, F10, F11, F12 Keys

What are the F1, F2, F3, F4, F5, F6, F7, F8, F9, F10, F11, e F12 Keys?

The F1, F2, F3, F4, F5, F6, F7, F8, F9, F10, F11, and F12 keys, also called function keys or FN keys, are a set of keys of the computer keyboard that when pressed execute some function. Which functions they have depend on which programs are running in the computer.

Where are they?

The function keys are located in the top part of the keyboard, between the Esc key and the Print Screen key. They're laid out in three groups of four keys each with a small gap between them: F1, F2, F3, F4, a space, F5, F6, F7, F8, a space, then F9, F10, F11, F12.

Observation: the function of the keys are influenced by their physical location: it's common for keys at the edges of each group to have common functions since they're easier to press, that is, F1, F4, F5, F8, F9, and F12 are more used than the other function keys.

What are they for?

The main difference between the function keys and other keys of the keyboard is that function keys are usually used as keyboard shortcuts without a modifier key (which are Ctrl, Alt, and Shift). That is, normally, a keyboard shortcut would contain a modifier key to avoid executing an action by accident when a random key is pressed, but with function keys his doesn't happen since their only purpose is to be a keyboard shortcut.

Common Functions

Some common functions of function keys, all by convention:

F1: displays "help" in applications that support this shortcut, what this means exactly varies from application to application. Nowadays few applications support this. In some casos, an application whose purpose is to display a manual or documentation of the application is displayed, the files of this manual would have been already installed in your computer when you installed the application. This was the case of Microsoft applications, such as Paint and Notepad, in the past—these days, pressing F1 in these will try to access Microsoft's website in a web browser and show the online manual, which is worse, in my opinion, as the "help" wouldn't be available if you aren't connected to the Internet. In some applications, pressing F1 turns the mouse cursor in a help cursor (typically featuring a question mark (?)) , and while in this mode, clicking on a button or another element on the window will display help related to it.

F2: renames an item in a list, works in various contexts. In a file manager, renames files and folders. In an image editor with layer support, e.g. Photoshop, GIMP, Krita, etc., renames the selected layer.

Alt+F4: closes the current window, such as this very window that you're looking at at this very moment.

F5: updates (refreshes, reloads) what's being displayed in a "browser" application, in the sense that it has an address bar. For web browsers, to update means to download the contents of the web page again from the website. By default, the browser doesn't know if the content of the page changed in the website, and can only display the last data that was downloaded, which means if you access a news website, for example, and let the browser open for 7 days, the latest news will be from 7 days ago since the news feed won't have been updated, so it shows the same thing as 7 days ago. Pressing F5 in this case would be like accessing the webpage in a new tab or window. Note that most modern web browsers are based on Chromium, which uses a browser cache technology. In these browsers, "updating" doesn't update the cached data. For this, we need to press Shift+F5, which clears the cache and reloads the page. In a file manager (also called a file browser), the data display, the files and folders, are loaded from a hard disk or SSD. Generally, the operating system is capable of alerting the file manager that files were added or changed in the folder that is being displayed, so it's not necessary to refresh manually, however it's still possible to do so pressing F5, since there are cases where this doesn't occur, e.g. if you're browsing a remote folder (from a server), the manager may not be alerted of modifications.

F12: when a video-game is run through Steam, F12 saves a screenshot that can be posted in your Steam account. Note that normally you would press the Print Screen key to take screenshots. The closest function key to this key is F12. So applications that take screenshots in a special manner typically make use of F12 as it's physically the closest to the normal key.

A special function of these keys is to serve as the key to enter the BIOS menu when a computer is turned on. Which key does this exactly depends on the motherboard. Generally it's F8, F9, F10, and needs to be pressed in a certain point after the computer turns on but before the operating system is started. Due to this a technician trying to enter the BIOS generally will mash every key that starts with F and restart multiple times trying to find the key that enters the BIOS.