The Fn is red on my Gateways Fn button. Your F1 Thru F12 buttons as well as the arrow buttons may have similar colored symbols on them. When the Fn button is pushed in conjunction with the button with the symbol you need it performs that function. Or, as someone already said, pushing the Fn button enables the secondary functions of the button that has a secondary function shown on it. On my arrow keys, the up and down arrow buttons become the brightness control buttons when the Fn key is pushed. The left and right buttons control volume. Just a way to get more functionality out of less buttons.