Extended desktop? Mirroring? What does that mean?
These are both methods for connecting your computer to an external screen or projector. Here’s the difference;
Mirroring
Mirroring is when the external screen and the internal screen display the same thing.
In an event situation this is preferred when doing a software demo or if the presentation is a PDF file (not recommended!). And sometimes we use this method if using a clients BYO a laptop which is a bit old, because mirroring uses less of the limited graphics resources.
Extended desktop
Extended desktop is when the external screen is additional to the internal screen.
In an AV situation this is preferred for running presentations so you can see your upcoming slides and notes on your local screen, while the audience only sees your current slide. This is called “presenter view” and Powerpoint and Keynote both have this function.
To quickly swap between these options, here are the shortcut keys:
MAC: Command+F1 (with touchbar Fn+Command+F1)
Windows: Windows+P