A sitemap is a file that contains the different pages of an Internet site and the route to them through the sections of the site. The web pages can be sorted visually or as plain text and this kind of a file is really useful for 2 reasons. The first one is that it makes it much easier for the website visitors to discover a specific page they need, which means that they can navigate your site better and much faster, which in turn will improve their user experience and it'll be more likely that they will come back to the Internet site or will recommend it to other people. Another reason is the fact that a sitemap enables search engines to index your content better, especially if it's updated, so when users are interested in certain content, it is much more likely that they'll come across your site as it will be listed higher in their search results. If your website is not indexed well, it might not show up for some searches, so even if you have what people want, they will simply not get to your Internet site.