If you use a Mac and iPad together, Sidecar can turn the iPad into an extra display without needing a separate monitor.
On a compatible setup, open Control Centre on your Mac, choose the display controls and select your iPad. The Mac desktop can then be extended onto the iPad, giving you extra space for Mail, Messages, reference material or tool palettes.
The connection can work wirelessly when both devices are nearby, signed in to the same Apple Account and have Wi-Fi, Bluetooth and Handoff available. A cable can still be useful if you want the most stable connection or need to keep the iPad charged.
Sidecar is different from simply mirroring the Mac. In extended mode, the iPad acts like a separate screen, so you can drag windows between the two displays.
Apple Pencil can also work with supported Mac apps while Sidecar is active, which can be useful for drawing, marking up documents or controlling creative tools.
If you already own an iPad, Sidecar is one of the easiest ways to get more screen space when travelling or working somewhere without a desk monitor.
