Mirroring on Your Mac

One thing that is sometimes confusing on the Mac is mirroring. Sometimes you plug in your projector and you get some random background or picture on your screen and a different one on your computer. What's going on? Or off? It's mirroring. Your computer has an option in System Preferences > Displays to either mirror exactly what's on your screen and throw it up on your projector (mirroring) or have one thing on your screen and another thing on your computer.

Let's say you wanted to show your kids an entry task while still taking your attendance. You can do this by turning mirroring off. First, make sure you have your projector plugged into your computer. Next go into System Preferences > Display you should see an option for Arrangement. On this page there should be two little screens. Simply move one to the left or right of the other. If there's a checkbox to turn mirroring on/off slide it to "off".

Now you can drag one of your applications, in this case your entry task, off of your screen and it will show up on your projector. Your attendance will not. When you're done simply move the little rectangles back on top of each other and turn mirroring back on.