To compare two PowerPoint 2013 presentations, you can follow these steps:

1. Open PowerPoint 2013 on your computer.
2. Open the first presentation you want to compare.
3. Go to the “Review” tab in the PowerPoint ribbon.
4. Click on the “Compare” button in the “Compare” group. A drop-down menu will appear.
5. Select the “Compare” option from the drop-down menu. A file explorer window will open.
6. Navigate to the location where the second presentation is saved, select it, and click the “Open” button.
7. PowerPoint will start comparing the two presentations and generate a new presentation that shows the differences between them.
8. The new presentation, called the “Comparison Presentation,” will open, displaying a slide-by-slide comparison of the two presentations.
9. Review the Comparison Presentation to see the differences between the two presentations. PowerPoint will highlight the changes in text, formatting, and other elements.
10. You can further analyze the differences by clicking on the slides in the Comparison Presentation and examining the detailed comparison view in the “Slides” pane.
11. If needed, you can save the Comparison Presentation by clicking the “Save” button in the PowerPoint ribbon or by pressing Ctrl+S. Choose a location and provide a name for the Comparison Presentation.

By following these steps, you can compare two PowerPoint 2013 presentations and easily identify any changes or differences between them.