Enabling Canonical URLs in Magento by Meta Tag is a good method to solve this problem by informing search engines the page with the same content to index.
The URL Rewrite allows store owners to change the URL connected with a product, category or CMS page. It will redirect the link pointing to the new address.
It is necessary for a site to be indexed by search engines for a better SEO. Hence, visit now to know easy steps to configure Magento 2 Robots.txt.
XML Sitemap determines which sitemap should be updated frequently if there appear any new changes about contents on a site (daily, weekly or monthly change)