By default Cassiopeia had full width header and footer. This design option is widely used on websites. 

But KickstartCassiopeia has the option to choose between a full-width layout or a boxed layout. With just one switch you can completely transform the look and feel of your site. As a broad rule, the full-width will give a more creative, modern feel to your website. The boxed-width style will make your website seem more traditional and professional. 

This feature is different from a fluid layout or boxed layout that you can set in the Cassiopeia template settings. When using a fluid layout here, the option in our module will not work.