Google Sitemaps - The Introduction
On the 2nd on June 2005 google announced the launch of Google Sitemaps into the BETA stage. The release was around the same time as Google was believed to have been making algorithm updates under the codenamed "Bourbon". The Google Sitemaps project is very interesting in helping the relations between webmasters and Google. Producing and submitting your site's sitemap in the correct format to google with both help make sure that Google is kept informed about any updates to your sites and any new pages that might have be added and that more of your content is covered in the Google index.
With this new project, Google hopes that it will help improve the coverage and freshness of the massive google index.
Google has mentioned that Google Sitemaps does not guarantee inclusion of all your pages into the SERPs. They are hoping the new system will improve on the traditional crawling system with webmasters using Google Sitemaps to hint how often content is up dated on their site.