Extend or mirror your Mac desktop across multiple displays
When you connect one or more external displays to your Mac, you can choose what appears on each display.
You can use video mirroring to show your entire desktop on each display.
You can extend your desktop across two or more displays, and choose which display shows the Finder and application menu.
If more than two displays are connected, you can specify that some use video mirroring and others use an extended desktop.
On your Mac, choose Apple menu
in the sidebar. (You may need to scroll down.)Click the name of your display on the right, click the “Use as” pop-up menu, then choose an option.
Note: If you are using a Mac laptop or iMac, you must have an external display connected to your Mac to see these options. If you are using a device with no built-in display, such as a Mac mini or Mac Studio, you must have more than one display connected to see these options.
To set up some displays for mirroring and others for an extended desktop, start by setting up all displays as an extended desktop. Then, press and hold the Option key, and drag one display icon onto another display icon to mirror those two displays.
