An XML sitemap is a file that lists the URLs on your website, helping search engines like Google and Bing discover and crawl your pages more efficiently. It is especially useful for large sites, new sites with few external links, or sites with pages that are not well linked internally.
Upload the generated file to the root directory of your website, so it is accessible at a URL like https://yourdomain.com/sitemap.xml. You should also reference it in your robots.txt file and submit it directly through Google Search Console and Bing Webmaster Tools.
The <priority> and <changefreq> tags are hints, not guarantees - Google has stated it largely ignores them for ranking or crawl-rate decisions. They can still be useful for other crawlers and for documenting your own sense of page importance, but do not expect them to significantly change how often Google crawls a page.
Yes - the sitemap protocol limits a single sitemap file to 50,000 URLs and 50MB uncompressed. If your site has more URLs than that, you will need to split them across multiple sitemap files and list them all in a sitemap index file.
No - this tool generates a sitemap from a list of URLs you provide, so nothing is uploaded or crawled. For large or dynamic sites, most CMS platforms (WordPress, Shopify etc.) offer plugins that generate and update sitemaps automatically, which may be more practical than maintaining one by hand.