Sitemap. There are two popular versions of sitemaps, and nopCommerce supports both of them. An XML sitemap is a structured format of a site that a visitor doesn't need to see. The sitemap gives information about the pages on a site to search engines: their relative importance to each other, and how often they are updated. HTML sitemaps are designed for users, to help them find content on a page. They don't need to include each subpage. HTML sitemaps help both visitors and search engine bots find pages on the site.
Should be installed and enabled first.