The feature is pretty self-explanatory. Using it, you can share documents, photos, or whatever else may be on your screen.
You can access it by tapping on the Share icon.
Then you choose whether you want to share a specific app only or your entire screen, no matter what.
If this sounds familiar, it's because Zoom and Google Meet's screen-sharing functions work in a very similar way.
As usual, the new feature is rolling out in a phased manner, so you may not see it right away.
It will be available on Android, iOS, and through the Windows desktop client for everyone in due course.
To complement screen sharing, WhatsApp is also allowing landscape mode video calls now.