A site map improves the way your store is indexed by search engines, and is specifically designed to find pages that might be overlooked by web crawlers. A site map can be configured to index all pages and images.
When enabled, LightRcommerce creates a file called sitemap.xml that is saved to your installation in the location that you specify. The configuration gives you the ability to set the frequency of the updates, and the priority for each type of content. Your site map should be updated as frequently as the content on your site changes, which might be daily, weekly, or monthly.