Sitemaps.org is a website created by Google, Bing, Yahoo, and Yandex to help webmasters easily create and submit sitemaps for their websites. A sitemap is an XML file that contains information about a website's URLs and their associated metadata, such as when the page was last updated, how often it changes, and its relative importance compared to other URLs on the website. Submitting a sitemap helps search engines better understand and crawl a website, as well as provide additional information to users. Sitemaps.org provides helpful resources, such as an XML sitemap generator and information on how to create and submit a sitemap. It is an invaluable tool for webmasters and website owners who want to ensure their website is properly indexed by search engines.