The dispute was over the innocently-named Site Finder Service, launched by Verisign in 2003. With traffic to every .com domain going through Verisign, the Site Finder Service redirected anyone accessing an unregistered domain (via a typo, for example) to a Verisign website with sponsored links. The company argued that this was more useful to Internet users than seeing a generic error page. Whatever their reasoning, this made Verisign the de-facto owner of every unregistered domain (what else does it mean to own a domain?), and skyrocketed them from 2,500th into the top 10 most visited websites. The best part? Verisign launched this without running it past anyone.
A domain name consists of one or more labels, each of which is formed from the set of ASCII letters, digits, and hyphens (a-z, A-Z, 0-9, -), but not starting or ending with a hyphen. The labels are case-insensitive; for example, 'label' is equivalent to 'Label' or 'LABEL'. In the textual representation of a domain name, the labels are separated by a full stop (period).
If you’re still with me then you might be wondering who came up with all of this. The answer is ICANN — the Internet Corporation for Assigned Names and Numbers. ICANN is a non-profit whose role is to coordinate all the names and numbers that keep the Internet online. They outsource a lot of the heavy domain name lifting to registries like Verisign, who pay ICANN for the privilege.
Registries and registrars usually charge an annual fee for the service of delegating a domain name to a user and providing a default set of name servers. Often, this transaction is termed a sale or lease of the domain name, and the registrant may sometimes be called an "owner", but no such legal relationship is actually associated with the transaction, only the exclusive right to use the domain name. More correctly, authorized users are known as "registrants" or as "domain holders".