Breadcrumb navigation sometimes appears at the top of the web page to show the website visitor what pages they visited to get to the page they are on. These breadcrumbs are also linked to that the website visitor can quickly go back to a past page that they were on. If done properly it would be in a silo architecture with the main topic at the top of the silo with sub-topics below them. This will improve internal linking and help with search engine results.