> Then, you start up Universal Control by dragging your mouse pointer all the way to the left or right edge of your Mac’s screen, then a little bit beyond that

> Then, you start up Universal Control by dragging your mouse pointer all the way to the left or right edge of your Mac’s screen, then a little bit beyond that edge. When you do, the Mac will assume that you’re trying to drag the mouse over to another device, in this case the iPad. That's really clever! Users of multiple screens already know to do that, and that also makes users get used to treating other devices just like another screen.