PowerPoint has a handy feature that allows you to freeze an object on a slide. By locking objects from moving, you will not worry about hitting the wrong object when aligning, grouping, or resizing the rest of the slide elements. Locking will also allow you to more easily work with the object's content without fear of automatically resizing or displacing the object when you edit its content.
The PDF file format is often used when it is necessary to prepare a PowerPoint presentation for printing, viewing, or e-mailing, as well as for format-preserving sharing and security purposes. The PDF version of the presentation can be viewed and printed by those who do not have PowerPoint.
Instead of opening the PowerPoint presentation file and then clicking F5 or using other ways to start the presentation, you can save your PowerPoint file in the PowerPoint Show format. Also, this format prevents changes in the presentation.