XMLSitemap
XML Sitemap is a file that lists the pages of a website in XML format, intended to help search engines discover and crawl content. The standard is defined by sitemaps.org, and the common file is named sitemap.xml located at the site root. The file uses the urlset element with the namespace http://www.sitemaps.org/schemas/sitemap/0.9. Each url entry includes a loc element with the page URL and may also include lastmod (the last modification date), changefreq (how often the page is expected to change), and priority (the relative importance of the page). There are also optional extensions for images, videos, and news items.
A sitemap index file can reference multiple sitemap files, using sitemap entries with loc and lastmod. This
Practical considerations include limits and generation methods. A typical sitemap may contain up to 50,000 URLs