Under Elements of the editing toolbar, there is an option for "Templates". These are specialized code snippets that are designed for adding standard code to your page.
Some of these templates are for general use and other are more specific. The six BOX templates add the text for a container around special text (E.g., a note box or an example box). The Embed templates are for special HTML5 interactive code like Jupyer executable code or interactive molecules. The other templates will be discussed in a different section. Feel free to add any of them to a test page to see what it does.