Let's say you want a second screen for your Mac to extend or mirror your current display. If you're running macOS Catalina or higher and own an iPad, you can do it through a feature called Sidecar.

Use Sidecar to extend a Mac to an iPad screen Setting up the iPad as a second display is, in typical Apple style, fairly straightforward.

If you need a second screen, you can use your laptop screen as an External Monitor to get more space for apps. See how it's done!

Duet Display lets you use any Android device as a second screen for your Mac, whether wired or wireless, giving you extra space for multitasking.

Extend your Mac's display onto a smaller, portable screen, by using your iPad as a secondary monitor and the Duet Display application for OS X and iOS.

Alex gives you a short tutorial on how you can use the app to extend the screen of your phone, tablet, or PC to the TV using the console.

Universal Control is coming in macOS Monterey, but you can use any device as a second monitor right now with the right software or accessories.

This article explains the Dual Screen and Extended Monitor options in Windows 8 and recommends the best option to be used in multiple monitor setups.

5 Ways to Extend Tablets Beyond the Screen Here’s how creative educators are using hardware and software to build a bridge between the digital and physical worlds. By David Raths 05/06/15 Osmo’s ...

With macOS Catalina's Sidecar feature, your iPad can be a second display for your Mac. You'll need a relatively recent Mac, but here's how to set it up and use Sidecar.