If you’re collaborating on PowerPoint presentations, sometimes it can be a challenge to know what changes others have made. While you can’t use Track Changes the way you can in Word and Excel, you can compare two versions of a presentation.
From a revised copy of the presentation, on the Review tab in the Compare group, click the Compare button. On the next dialog box, click the Merge button. You’ll see a task pane on the right called Revisions showing the changes and notations on the slide thumbnail in the navigation pane on the left. Hover over these for more information.