Question about the key F7

[kimcheeboi65]

Sorry for the third post by me within 30 min, but I am a new Mac user.

I love the keys F9, F10, F11 and all the 4 corners.

I see how all the F# keys work except F7.

It has two rectangles over one another and I have no idea what it does.

Any help?

Thanks

 

[mad jew]

If there are multiple screens you can switch between mirroring (same image displayed on both screens) and extended desktop mode with F7 to the best of my knowledge.