What do the dotted lines mean?

Click on the Edit button in the Admin Toolbar.  You'll notice dotted lines around certain areas of the site.   This denotes what areas of the page you can edit content on. 

If you move your mouse cursor over top of the dotted area, an edit button will appear.  Clicking on the edit button, will allow you to edit the content within the dotted lines.  If a green New button does not appear, it indicates this dotted area is the page content.

If no Edit button appears, the page type you are viewing may not be editable.  Contact the support team to see if changes the desired changes are possible to make on this page.

If a green New button does appear, it indicates this dotted area is for widget content.

You'll learn more about widgets in section 2.