The Main Index page will by default display the Slider followed by four Featured Tabs ('Tabs' for short). However the Tabs are not only optional in the Main Index but can be pulled in to any page template of your choosing. You may only have one set of Tabs on each page so once you have called either the Tabs or the Slider-Tabs module any further calls to the Tabs or Slider-Tabs modules will be ignored.
Calling these 'Featured Tabs' is a hangover from the Scouts 4 WordPress theme. You might consider that they aren't really 'tabs' at all.
Each Tab is a dynamic sidebar (with any 'title' supplied by widgets being left unwrapped), but if there isn't a widget the Tab will display configurable text that is linked to one of the standard URLs built in to the theme. The default text and links are the names of the three youngest sections plus 'Adult Volunteers'.
The colour of each of the Tabs is configurable to one of the Scout brand colours with the default being purple for the first three and mauve for the last one.
The Scouts 4 WordPress theme displayed the latest post in the default category in the first tab. This design feature was rejected for this theme because the latest post isn't always the one that needs highlighting, and also the title of the post could be too big for the tab. However the ID of a post or page can be defined for each of the tabs and it will be linked to using the title, so the same effect can be achieved manually.