1- It crawl your website finding all of its pages, including pages that can't be found by search engines' crawlers, to create an XML Sitemap and SEO dashboard report.
2- It submit your XML Sitemap directly to the XML interface of major search engines such as Google, Yahoo!, Bing and Ask — plus help you find and fix SEO errors.
3- The search engines use your XML Sitemap to drive more qualified traffic to your site by indexing more pages in search results.