This is a section that is hidden by default, and if someone clicks on a button / arrow it will opens up. Lots of theme has this option. (its not toggle!)
Do you have an example of what you mean exactly :)
@UX Themes: Hi, here is an example link:
In the edge of the sections there is a + button that shows the additional info
@UX Themes: Hi! Yes I will search for it. Its like a "Load more" button that shows more information about a topic. I often see this on landing pages.