Sidebar: This sidebar is the default sidebar area. This sidebar area is displayed on the blog page, archive pages, single blog pages, 404 page, search page, and other pages.
Below Banner Primary Widgets Area: This sidebar is displayed in the middle of frontpage section. You can add widgets that you want to display beside the secondary widget.
Below Banner Secondary Widgets Area: This sidebar is also displayed in the middle of frontpage section. You can add widgets that you want to display beside the Primary widget.
Above Footer Widgets Area: This sidebar is displayed just above the footer section of frontpage section.

If you want to add a widget area in the footer then you must add widgets in Footer Widget 1, Footer Widget 2, Footer Widget 3, and Footer Widget 4.