When it comes to using a Windows laptop as a second screen for a Windows desktop, the secret ingredient is the streaming standard Miracast, so no cables or connections of any kind are required.

How to extend your Mac's desktop with an iPad and Duet Display Our third and final method is especially good if you already carry an iOS device with your Mac.

Apple continues to explore ways of extending or improving the iMac, this time by working on integrated technology to extend the user's screen by projecting displays onto nearby surfaces such as walls.