Ummmmmm
Going on the theory behind DNS, it shouldn't make a difference.
ALL domains actually have a . on the end, referred to as the root domain.
When you try to get to
www.google.com (or
www.google.com. [;)]), your computer first queries the root server (.) to ask if it knows where the server is.
Of course it doesn't know, but it refers it to the .com server, which your computer trots off to ask.
The .com server doesn't know, but it knows where google.com is, so it refers you there.
google.com knows the location of
www.google.com (it's on the same network), so it gives you the IP address.
OK, so any techies will be crying now, because this is not strictly true (there's a LOT more to it), but it gives you the general just of DNS