What is the difference between a Registry and a Registrar?

A registry provides direct services to registrars only, not Internet end-users. The Registry database contains only Domain Name service (DNS) information (Domain Name, name server names and name server Internet Protocol [IP] numbers) along with the name of the Registrar that registered the name and basic transaction data. It does not contain any Domain Name Registrant or contact information. A Registrar provides direct services to Domain Name registrants. The Registrar database contains customer information in addition to the DNS information contained in the registry database. Registrars process name registrations for Internet end-users and then send the necessary DNS information to a Registry for entry into the centralized Registry database and ultimate propagation over the Internet.