The widgets you place here will organize themselves in two columns before the footer. The subsidiary two column widget area allows you to set the widgets in three columns above the footer area. It will be available on all the pages.
You can also use the Subsidiary – 1 Column and Subsidiary – 3 Column widget areas to display the content. All three widget areas Subsidiary – 1 Column, Subsidiary – 2 Column and Subsidiary – 2 Column can also be used together.