What is Google's Sitemap Submission?
A sitemap is a file/URL on your website where you provide information about the pages, videos, and other files on your site, and also if and how they may be linked to each other. Search engines like read this file so they can index and crawl your site more effectively. A sitemap will tell search engines which pages and other media files you regard as most relevant to your website.
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Google's Sitemap Submission Discounts