A Sitemap is an HTML page that lists links (URLs) to all the different pages in a website, typically organized in hierarchical fashion. A Sitemap page will help your visitors to better navigate within your own website. Sitemaps are beneficial in cases when it is difficult for users to access all areas of a website through the browse-able interface.
A Sitemap Page is especially important if a website uses Macromedia Flash or Java Script menus that do not include html links.
The Google Sitemap allows webmasters to inform search engines about URLs on their website that are available for crawling. The Google Sitemap is actually an XML file that lists the URLs for a site using the Google Sitemap Protocol. The protocol was written to be highly scalable so it can accommodate sites of any size.
Sitemaps are beneficial in cases when it is difficult for users to access all areas of a website through the browse-able interface. For example, any site where certain pages are only accessible via a search form would benefit from creating a Google Sitemap and submitting it to search engines.
