Google XML Sitemap

Google XML Sitemap improves search engine rankings by helping search engines crawl through, index, and classify webpages. Sitemaps also help with navigation, allowing your website's pages to be found quicker by search engines. Certain webpages are usually not understood by search engines, such as those written in Flash or rich AJAX. Big databases can also create a problem for search engines. So, if your website has databases or contains pages written in Flash or AJAX, your website most definitely need a Sitemap. Most other websites will also benefit from having a site map.

Google XML Sitemaps are files that list every webpage (or URL) on a certain website. These Sitemaps are written according to XML (Extensible Markup Language) specifications, making the file readable to most search engines. A Google XML Sitemap also lists other information helpful to crawlers: how important the webpage is compared to other pages on the site (is this a key page?), the date the page was last updated, and the usual time period between updates (so the search engine knows how often it needs to send crawlers through the site to get updated content).

Initially released just for Google, all 4 of the most popular search engines now use Google's XML Sitemap protocol: MSN, Ask, and Yahoo! as well as Google.