Function buttons (F1, F2, ... F10 etc.) are usually located in the top row of keys on your keyboard. Location may be different on different keyboards.
FN is a function key and it's position really depends on the make of the keyboard. On my keyboard it's blue; therefore, any blue above a normal keyboard key will represent what will have if I press...
it is exactly like a symbols button, you press it and you can incert different symbols like ( ! # $ @ * & ?) hope this helped!
the top 2, never the last button
All 4