What is ROR sitemap and how its different from Google sitemap

Sitemaps are an easy way for webmasters to inform search engines about pages on their sites that are available for crawling. In its simplest form, a Sitemap is an XML file that lists URLs for a site along with additional metadata about each URL (when it was last updated, how often it usually changes, and how important it is, relative to other URLs in the site) so that search engines can more intelligently crawl the site.

Web crawlers usually discover pages from links within the site and from other sites. Sitemaps supplement this data to allow crawlers that support Sitemaps to pick up all URLs in the Sitemap and learn about those URLs using the associated metadata. Using the Sitemap protocol does not guarantee that web pages are included in search engines, but provides hints for web crawlers to do a better job of crawling your site.

ROR site map promotes the concept of structural feeds or in XML format.While Google Site map creates a site map with HTML and images format .

Google site maps page was showing about 25000 pages to be in database, however it had indexed only 6-7000 pages. when we did checking, we noticed that our site map format was not exactly as per Google specification. it was more of a RSS site-map. we think that XML site-map is the best of all solution as far as site map for search engines is concerned. but there should not be harm in maintaining ROR site map too, though may not be of much advantage either. 

Actually a Google sitemap is in XML and is now the default format for all four major search engines. That's why Ror sitemaps are worthless. It's not only redundant but ignored by the search engines. Ror sitemap promotes the concept of structural feeds or in XML format. While Google Sitemap creates a sitemap with HTML and images format.

ROR expands on the RSS protocol with its own extensions. The standard file extension for ROR files is .ror. All search engines that understand RSS sitemap files continue to understand the RSS parts of ROR files. However, no major search engine currently supports the ROR sitemap extensions.