Sitemap: what it is, what it is for and how to submit it to Google

The sitemap is a navigation map for crawlers who sift through the network in continuous search for new sites and content to offer the users. It is a useful tool that makes crawling easier and more efficient and effective. In this article we will try to provide a quick guide to the sitemap, and to answer the main questions about this "ancient" but still useful file. What is it for, how is it created, does it have value for SEO?