A sitemap is a method of website organization that identifies the URLs and data under each section that was mostly geared toward website users. The XML sitemap format was designed by Google to allow search engines to find data faster and more efficiently in response to the increasing size and complexity of websites.
XML protocol allows search engines to optimize their search by placing all URL information on a single page. It also determines how often a website is updated and records the last time changes were made to the website. It does not affect ranking but does allow for more accurate searches and rankings. Yahoo and Microsoft now support the XML protocol so that webmasters no longer need to create different types of sitemaps. One can be created for submission and updated when changes are made to simplify the process to that content is picked up by all three leading search engines.
The free XML Sitemap Generator from XML-Sitemaps will completely crawl your website. It will generate a details page that includes the number of pages, a broken links list, XML file content, along with a link to a compressed sitemap. You can download the file and place it in the “public-html/” folder on your site. You can then add your sitemap URL to your Google Webmaster account. The tool will index a maximum of 500 pages. An unlimited version can be purchased for $19.95 without the installation service, $29.99 including installation service.

