A sitemap or site plan is an XML file that is used to signal the pages of your site to search engines. In summary, an XML Sitemap (commonly called Sitemap) is a list of the pages of your website. It is generated automatically, but you can always modify it.
It is recommended to always add a Sitemap to help your SEO.
To add a sitemap, access the Toolbar and click on Settings, then on ‘SEO’ on the menu bar on the left. The ‘Yes’ field is checked by default.
If you choose not to automatically add your sitemap, you will need to add your sitemap manually as you add new content on your site. Be aware that mishandling the contentcan render the file invalid, causing it to be unusable by search engines. Do not modify it unless you are an experienced Webmaster.
You have also the option to list or conceal the hidden pages in the sitemap.