Registries manage the sale of all domains for the domain endings (top-level domain or TLD) that they own. You can think of a registry as the wholesale and the registrar (Google Domains) as the retail. Customers, individuals, businesses and organisations buy domain names from the registrar, and the registrar registers the domain names it sells with the registry.
Each registry manages the administrative data for the domains and subdomains under its authority, including the zone files that contain the addresses of the name servers for each domain. Each registry maintains a database that contains registrant information for the second-level domains (google.com, example.com) beneath the top-level domains (.com) that the registry manages.
A registry operator is an organisation that maintains the administrative data for one or more top-level or lower-level domains. For example, VeriSign is responsible for several top-level domains, including the .com, .net and .name domains. A registry operator is given authority for a domain through ICANN.
Some registries have specific terms of service documents for the domains that they sell. These spell out the rights, responsibilities and requirements for registrants (customers), registrars and the registry. When you purchase a domain name, you must agree to these terms of service. Review our list of domains endings for more information on their registries.