A sitemap is a visual or text map of a site - a list of all web pages arranged in sections as they appear on the website. The sitemap is a single file and its presence could have a substantial influence on the popularity of your site, particularly if you have a lot of content. It will permit your website visitors to search the pages and find what they need much quicker, which will increase the possibility for them to revisit the website or to show it to friends and colleagues. The sitemap is also needed for search engines like google to index your content better, which means that certain pages will show up in the results for certain searches, which will most likely not happen without having a sitemap even when you have the necessary content. This is especially valid if you update some web pages as the sitemap informs the search engines that they must crawl the website again in order to index the latest content. Having a sitemap nowadays is a necessity rather than an optional feature for every successful Internet site.