Dell Inspiron 14-3480 Manual page 24

Function key
The Fn key is also used with selected keys on the keyboard to invoke other secondary functions.
Tableau 24. List of keyboard shortcuts
Function key
24 Keyboard shortcuts
Re-defined key (for multi-media control)
Behavior
Turn off/on wireless
Pause/Break
Sleep
Toggle scroll lock
Toggle between power and battery-status light/hard-drive activity
light
System request
Open application menu
Toggle Fn-key lock
Page up
Page down
Home
End
Behavior
Increase brightness