Site maps are very useful for a website. there are 2 types of websites search engine site map and User site map.An HTML site map is a page within your site that links to all the other important pages on your site.
HTML site map is important, two main reasons i am telling you why?
it helps search engines crawl and understand your site, and it helps human visitors browse your site more efficiently
HTML sitemap is not necessary to create for a website. This is mainly done for the visitors. When you have a large website with number of pages, then you need a sitemap to let your users know about the new pages of website.
It is not really needed, but might be useful for users as well as search engines. In our experience Google will find many also more or less hidden pages and recently seems to deal with parameters very well. We also use the canonical and that also seems to work very well. Sitemaps may help Google index your site faster though.
By submitting sitemaps, you inform or request search engines to crawl your website for the changes you made.HTML site map is used for clear visibility of website and XML site map is used for better indexing within the search engine results.