An XML sitemap is an XML file where you provide information about the pages, videos, and other files on your site, and the relationships between them. Questions related to how XML sitemaps affect SEO are off-topic for Stack Overflow. They may be on-topic at the Webmasters Stack Exchange.
An XML sitemap is an XML file where you provide information about the pages, videos, and other files on your site, and the relationships between them. Search engines like Google read this file to more intelligently crawl your site. A sitemap tells Google which pages and files you think are important in your site, and also provides valuable information about these files: for example, for pages, when the page was last updated, how often the page is changed, and any alternate language versions of a page.
The standard for the protocol can be found at https://www.sitemaps.org/
Here is the format of a basic XML sitemap:
<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
<url>
<loc>http://www.example.com/</loc>
<lastmod>2020-01-01</lastmod>
<changefreq>monthly</changefreq>
<priority>0.8</priority>
</url>
</urlset>