Sitemap is the most important part of a site and its SEO campaign. SEO's primary target is to get high on SERPs and increase the organic traffic to the site. But, before anything get started regarding SEO, if we dont inform search engines that our site exist and tell them our site's address then getting any other SEO processes done, is all in vain.
An XML Sitemap works as a business card and invitation to the search engines with detailed link information of the site's pages and properties, which help them to locate, crawl and rank your site depending on all other SEO techniques and tactics. So do not ever forget to generate an xml sitemap for your latest content and submit it to the search engines.
Using sitemaps has many benefits, not only easier navigation and better visibility by search engines. Sitemaps offer the opportunity to inform search engines immediately about any changes on your site. Of course, you cannot expect that search engines will rush right away to index your changed pages but certainly the changes will be indexed faster, compared to when you don't have a sitemap.
There are two types of sitemaps one is HTML and another one is XML.XML site maps stores the data as well as shows the data on the other hand HTML sitemap only shows the data they can't stores the data.Hence XML site map is better and important also.
As we know there are two types of site map one is xml site map and 2nd is html site map.
html site map is used for the visitors to easily navigate the site, where as we submit xml sitemap for search engines, but its not guarantee that after submitting the xml site map your site pages will be indexed, because after submitting site map we have seen many times that some page remain unindexed.