If your presentation has a number of Sections, you may find it little difficult to reorder your Sections by just dragging and dropping. Or you may even find it difficult to see all Sections at the same time. This happens because there may be many slides within each of these Sections. And if you want to drag a slide between the one Section to another, you may be at a loss to comprehend what you will end up with. So to counter this problem, you can collapse and expand single and multiple Sections, as explained in this tutorial.