According to Wikipedia, fully qualified host names end with a trailing period. Jonathan de Boyne-Pollard writes in No, that dot in the domain name of the URL is not a mistake (emphasis mine):
I omitted the trailing dot in the domain name in the http://example.com./ URL because it was a typographical error.
No, it wasn't. It was there for a reason. It made the domain name a fully qualified one, and thus unambiguous and not prone to search path spoofing.
I can use relative host names to refer to hosts within the same domain. What would happen if I set up a host named
com on a local network?
google.com. should still refer to Google as it's clearly fully qualified, but what about
google.com? Shouldn't it refer to the machine in my local network? Would it? Why (not)? What network setup or services influence the behavior?