Sidecar is the new feature of Catalina that allows you to use your iOS 13 (iPadOS) iPad as a secondary screen. But it is more than just a monitor as you can use touch and the Apple Pencil along with it.
Note: This is Club MacMost exclusive content. To view this video click the thumbnail below to go to the post as Patreon.com. Once there you will be able to view the video as long as you are logged into your Patreon account and a current supporter of MacMost at the "Club MacMost" or higher level.
