Shopstar! has a total of 3 sidebars. Pages can be configured to display any of these sidebars by setting the Template that they use to the appropriate template.
The Primary sidebar is the default sidebar. This means that if you create a page and don’t change the Template to something other than the default template by default it will display the Primary Sidebar on the right. The primary sidebar is also the sidebar that displays on the right of the Blog pages when the Blog isn’t set to Full Width Mode.
The Secondary sidebar is an additional sidebar that can be used for displaying additional widgets that you might not want to show in the Primary sidebar. This can be handy if your website has a Blog as the Primary sidebar would typically have Blog related widgets such as Recent Posts, Post Archive, Blog Search, etc. You probably don’t want to display these widgets on every page of your site and that’s where the Secondary sidebar can be put to use.
The Shop sidebar is the sidebar that will used by WooCommerce shop pages when it’s not set to Full Width Mode.