A Sidebar is a single column of Widgets which can be saved together and added to multiple pages as a group of widgets.
It saves you needing to manually recreate or manage a set of Widgets which are to identically sit on several pages.
This is useful if you have some pages which are all of similar topic or theme. For example, if you have some youth pages, calendar and video channel, the same ‘youth’ Sidebar could be applied to all these pages.
A Sidebar is optional and always displays on the right side of a page if used.