fn Key on Laptops (Function Key)
On most Mac laptops, there is a key with the tiny symbol fn on the bottom-left, in a different color. You see other keys with tiny symbols or characters also in that color, such as num lock, clear, home, end, pg up, pg dn (page up or down), as well as numbers. Also check the Fkeys. If you press the fn key, then the keys change their standard function to the symbols or characters in that matching color (the color that matches the fn), as described below.
F5 Num Lock F7 Insert (used in some applications) F8 Forward Delete
This shows the regular keys on your keyboard when you do not press the fn key.