Overlays are a powerful feature that allows you to toggle content on and off your page.

How to create an overlay

To use the overlay, use insert > overlay. Then put an object, text, or shape of what you want to have appear when an overlay link is clicked. 

How to use an overlay

Once the overlay is created, create a button or hyperlink to the overlay

Then, when the link is clicked, it will toggle the overlay off/on.