Sitemaps are a great tool for both web designers and visitors. Of course, there are two different types of sitemaps, 1) XML sitemaps (also known as Google sitemaps) and 2) HTML sitemaps. Each type serves its own purpose.
An HTML sitemap can be used effectively to increase the usability of a website by providing a page that links out to every page on the site (or at least to the major pages, depending on the size of the site). Navigation is of course one of the most important aspects to creating a user-friendly site, and when visitors aren’t able to easily find what they are looking for, many will turn to a sitemap. As a result, the HTML sitemap can help to keep visitors on your site by showing them where to find specific information. Additionally, because the sitemap links to all of the other pages on the website, they can be helpful to search engine spiders as they are crawling through the site.