An XML Sitemap Generator is a tool used to create XML (Extensible Markup Language) sitemaps for websites. These sitemaps provide a structured list of URLs on a site, making it easier for search engines like Google to crawl and index web pages. This aids in improving a website's search engine optimization (SEO) by ensuring that all important pages are discoverable. Users typically input their website's URLs, and the generator then creates a file with a list of these URLs in a format that search engines can understand. This facilitates better search engine visibility and ultimately enhances a website's online presence.