A sitemap is a visual or text map of a website - a short list of all webpages grouped in sections as they show up on the site. The sitemap is a single file and its presence can have a significant impact on the popularity of your site, especially when you have a lot of content. It will enable visitors to browse the webpages and find what they need considerably faster, which will raise the possibility for them to come back to the website or to share it with friends and colleagues. The sitemap is also needed for search engines like google to index your site content better, which means that some pages will appear in the results for specific searches, which will most likely not happen without having a sitemap even when you have the required content. This is especially valid in case you modify some pages because the sitemap informs the search engines that they must crawl this website again so as to index the new content. Having a sitemap these days is a necessity rather than an optional attribute for any prosperous Internet site.