Thats the difference between a domain name and a fully qualified domain name. If you've ever administered BIND, you'll note that you need to add a ending . to

Thats the difference between a domain name and a fully qualified domain name. If you've ever administered BIND, you'll note that you need to add a ending . to A records. Thats the FQDN. Now, our browsers link cookies to domain. And interestingly enough (example.com)!=(example.com.) That's why sites like nytimes.com. gets around the paywall, because you don't have a cookie history with that site.