Universal Control lets a Mac keyboard and pointer operate an iPad while the iPad continues running its own applications. This suits a task that needs an iPad app beside Mac work. Sidecar instead displays Mac windows on the iPad, so choose the intended behaviour first.

Apple requires a compatible Mac using macOS Monterey 12.4 or later and a supported iPad using iPadOS 15.4 or later. Check the linked model list: operating-system versions alone do not establish eligibility, and the 2017 13-inch MacBook Air is excluded.

Both devices need the same Apple Account with two-factor authentication, Wi-Fi, Bluetooth and Handoff. Keep them within ten metres, with internet sharing off on the Mac and mobile connection sharing off on the iPad.

Connect and identify the active device

In macOS Ventura 13 or later, open Displays settings, Advanced and enable the option allowing the pointer and keyboard to move between nearby devices. On iPad, enable Cursor and Keyboard under General, AirPlay & Continuity or AirPlay & Handoff.

Wake and unlock both devices. Push the Mac pointer past the screen edge toward the iPad to connect. Apple also provides arrangement controls and a Link Keyboard and Mouse choice for disconnecting a device.

Open a harmless editable note on each device. Move to the iPad, select its text field and type a short test phrase. Return to the Mac and type a different phrase. Confirm which application received each entry before attempting real work.

Make crossing the boundary deliberate

Keep the two test documents recognisable. Similar application windows can make it easy to forget which device is active even when the pointer moves correctly. Check the insertion point before typing a command or pasting private content.

Disconnect the iPad through the documented display controls and verify that ordinary Mac input still works. Reconnect once to confirm the routine is understandable.

Accept the arrangement when you can select the intended device, enter text in the correct application and end the connection. A shared keyboard is a navigation convenience; each device still needs its own suitable application and access to the work.

References: Apple: Universal Control.