
Keys from F1 to F12 are commonly known as "function keys", A function key is a key on a computer or terminal keyboard which can be programmed so as to cause an operating system command interpreter or application program to perform certain actions, a form of soft key.On some keyboards/computers, function keys may have default actions, accessible on power-on.
F1
- Almost always used as the help key, almost every program will open the help screen when this key is pressed.
 - Windows Key + F1 would open the Microsoft Windows help and support center.
 - Open the Task Pane.
 
F2
- In Windows commonly used to rename a highlighted icon or file.
 - Alt + Ctrl + F2 opens a new document in Microsoft Word.
 - Ctrl + F2 displays the print preview window in Microsoft Word.
 
F3
- Often opens a search feature for many programs including Microsoft Windows.
 - Shift + F3 will change the text in Microsoft Word from upper to lower case or a capital letter at the beginning of every word.
 
F4
- Open find window.
 - Repeat the last action performed (Word 2000+)
 - Alt + F4 will close the program currently active in Microsoft Windows.
 - Ctrl + F4 will close the open window within the current active window in Microsoft Windows.
 
F5
- In all modern Internet browsers pressing F5 will refresh or reload the page or document window.
 - Open the find, replace, and go to window in Microsoft Word.
 - Starts a slideshow in PowerPoint.
 
F6
- Move the cursor to the Address bar in Internet Explorer and Mozilla Firefox.
 - Ctrl + Shift + F6 opens to another open Microsoft Word document.
 
F7
- Commonly used to spell check and grammar check a document in Microsoft programs such as Microsoft Word, Outlook, etc.
 - Shift + F7 runs a Thesaurus check on the word highlighted.
 - Turns on Caret browsing in Mozilla Firefox.
 
F8
- Function key used to enter the Windows startup menu, commonly use to get into Windows safe mode.
 
F9
- Opens the Measurements toolbar in Quark 5.0.
 - Refresh document in Microsoft Word.
 - Send and receive e-mail in Microsoft Outlook.
 
F10
- In Microsoft Windows activates the menu bar of an open application.
 - Shift + F10 is the same as right-clicking on a highlighted icon, file, or Internet link.
 
F11
- Full-screen mode in all modern Internet browsers.
 
F12
- Open the Save as window in Microsoft Word.
 - Shift + F12 save the Microsoft Word document.
 - Ctrl + Shift + F12 prints a document in Microsoft Word.