• Computer keyboard usually have 12 function keys.computer keyboard image by Tom Curtis from Fotolia.com
  
  A computer keyboard is a tool used to operate a computer. Before the introduction of the mouse, communication was performed through the keyboard. Without point-and-click menu options, function keys were implemented to create common short cuts. These keyboard functions are still available with the F1 through F12 keys, which typically are found in three clusters of four keys each. In most applications utilizing the function keys, additional functions are defined by using a combination of the Alt key or Ctrl key with the function key.
  
  

F1 through F4

• The F1 key is typically used as a "help" key.
  
  The F2 key renames highlighted icons or files in Windows.
  
  The F3 key commonly is used to start a search option in many programs.
  
  The F4 key, in many applications, opens a find window.
  
  

F5 through F8

• The F5 key is used in most Internet browsers as of 2010 to refresh the screen or reload the page.
  
  The F6 key can move the computer cursor to the address bar in Mozilla Firefox or Internet Explorer.
  
  The F7 key commonly is used to run spell checkers or grammar checkers in some software applications.
  
  The F8 key typically is used to start Windows in safe mode from the start-up menu.
  
  

F9 through F12

• The F9 key has no function in Windows, but it may be assigned various other functions in other software applications.
  
  The F10 key activates an application's menu bar in Windows.
  
  The F11 key is used to designate full screen mode in most browsers.
  
  The F12 key opens the "save" window in Windows.