With the second developer beta of macOS Sequoia, Apple has added support for iPhone Mirroring, one of the main updates coming to the Mac. iPhone Mirroring is a Continuity feature that lets you control your iPhone from your Mac.
When you’re signed in to the same Apple ID on a Mac and an iPhone, you can use iPhone Mirroring to interact with your iPhone even when the iPhone is locked. You can open up and use apps, deal with notifications, send messages, and more.
You can use your Mac keyboard, trackpad, or mouse with your iPhone, which is useful for typing up long emails and other documents on the iPhone, and it provides an easy way to keep up with your iPhone notifications without having to pull out your device and check it. When you click on a notification on your Mac when using iPhone Mirroring, it is supposed to open up right into the app on your iPhone.
Read more at MacRumors.com