WordPress uses the Search Engine Visibility setting to enable or disable the visibility of your site to search engines. The value of this setting is stored in the wp_options table of your WordPress installation. We are allowed to configure this setting in the initial installation process. Sometimes, we disable it to discourage search engines from finding our site until it's built and published for public access. In such cases, we can disable this setting so that WordPress will start allowing search engines to index our site.

If the Discourage search engines from indexing this site option is ticked, WordPress will add a meta tag to the header of the site as follows:

<meta name='robots' content='noindex,nofollow' />

This line tells the search engines not to index the posts and pages or to follow the links on them. Once we uncheck the Search Engine Visibility setting, this meta tag will be removed, allowing search engines to browse and index the site.