Global Sidebar Position: This option works on all archive pages like 404, search, date, category, blog, and so on. You can choose either the Right sidebar or the left sidebar, or No Sidebar.
Post Sidebar Position: This option works only on single posts. You can choose either the Right sidebar or the left sidebar, or No Sidebar.
Page Sidebar Position: This option works only on a single page. You can choose either the Right sidebar or the left sidebar, or No Sidebar.