A domain name is registered through a company called a "registrar", which creates the domain name and allows the owner to manage it. The registrar is responsible for maintaining the domain's listing with the central "registry" and "root servers".

The registry is the organization that keeps track of all domain names of a particular TLD, regardless of which particular registrar was used to register them. The TLD, or Top Level Domain, is the part of the domain name following the dot, like .com or .org. The registry for each TLD maintains a central list of all domains within that TLD so that the same name cannot be registered by 2 different registrars, allowing names to reliably point to the same servers.

The root servers also maintain a unified list of domains registered by all registrars, but these records are technical, intended for use by computers rather than people. There are a number of different root servers maintained by different groups, each holding a complete list of the nameservers and other technical information regarding domains from all registrars. This is where machines look first when trying to resolve a domain name to a server.