If you develop a presentation collaboratively with a group, multiple versions of the same presentation may exist. PowerPoint allows you to compare and merge different versions of a PowerPoint file.
Before comparing two presentations, make sure that one of the two is currently open.
Click the Review tab.
If necessary, expand the Compare group.
Click the Compare button.
Navigate to and select the presentation you want to compare to the open one.
Click the Merge button.
PowerPoint merges the selected presentation with the one that you had open, and displays the merged file in Review mode. The Revisions pane opens at the right, listing all changes to the presentation.
There are two sections on the Details tab in the Revisions pane:
Slide changes: Lists all of the changes that were made to the current slide.
Presentation changes: Lists all of the changes that were made to the presentation as a whole.
Once you're comparing two presentations, you can review the differences between the two and choose which revisions to keep. After you've reviewed all of the differences, you can then save the approved changes into the open presentation.
Select a change in the Details tab of the Revisions pane.
A box appears on the slide, detailing all the changes to the object or text.
To preview what the slide would look like with the changes accepted, click the Slides tab on the Revisions pane.
Do one of the following:
Accept a change: Select the check box for the change or changes that you want to make.
Reject a change: Do nothing; keep the check box unchecked.
Use the Previous and Next buttons on the Review tab to move through the revisions, accepting or rejecting all of the revisions in the presentation.
Expand the Compare group if necessary.
Click End Review.
You need to verify that you want to end the review and discard any changes you rejected.
Click Yes.
Click Save.
The changes from the other presentation are saved into the open one.