If you have a second monitor connected to your Mac, you can turn it off at any time by following these simple steps:
- Open System Preferences.
- Click on Displays.
- Click the Arrangement tab.
- Uncheck the “Mirror Displays” box.
- Click the “Detect Displays” button.
- Click the “Turn Off” button next to the second monitor.
That’s all there is to it! Your second monitor will now be turned off and you can go about your business as usual.