A Sitemap is an XML data file on your site that lists all of your site's pages that are available for crawling together with other useful information like last update times and crawling priority. Sitemap files help Search Engines find all your pages to give them the highest chance of being indexed and ranked.
We recommend always having a Sitemaps file in place for your site. Sitemaps can be created manually using a utility, Wordpress plugin, or your CMS's Sitemap creation process. Additionally, the Sitemap should be referenced in your robots.txt file.