ok thanks for that.
I knew search engines follow links to look for pages to potentially index but I thought they somehow also traveled from domain name to domain name looking for potential website home pages (and subsequent sub pages if any) to index.
I am thinking of the scenario where a brand new website is launched with no links to it anywhere else on the www. Even without any other links to it on the www and without submitting the website (via a sitemap.xml) to Google for indexing, I thought that a Google bot would eventually still find the website. Whether any pages on the website are then subsequently indexed by Google is another issue.
Anyway, I'm digressing now

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