Sitemap refer map of a websites. It contains the structure of the sites, its section, the link between them etc. On a single page. And sitemap is important for website because sitemap is a easy way for webmaster to tell the search engine and user the websites structure
there are two type sitemap xml and html. xml site map is helpful for crawling your website by search engine and html sitemap helpful for visitor, its provide all link of the website at one page so visitor can get any link in easy way.
Sitemap is tell everything about your website.
sitemap threw easily show website's webpage
detail and when google crawler come to crowl
this page this can easily take information and
crowl all content.this is one type of easy way
for webmasters to inform search engines about
pages on their sites that are available for crawling.
and google generate dofollow backlink.