Key terms

This page provides key terminology that applies to Cloud Domains. Review these terms to better understand how Cloud Domains works.

Cloud Domains terms

The following key terminology describes the concepts on which Cloud Domains is built.

Domain Name
A domain name is a character string comprised of several parts, called labels, which are separated by dots to represent the domain hierarchy. Domain names have a domain ending corresponding to their registry operator. Domain names may be equivalently written in either unicode or punycode.
Domain Name System (DNS)
DNS is a hierarchical distributed database that stores IP addresses and other data and allows queries by name. To learn more about DNS, see the DNS overview page.
Domain ending or top-level domain (TLD)

A domain ending is the last label(s) in a domain name, like .com. Thousands of endings exist, and each ending is controlled by a registry. Customers of a registrar purchase domain names that are a single label plus the domain ending, like

Often, the domain ending is just a single label like .com, in which case the domain ending is also the top-level domain (TLD). In some cases, a registry controls a multi-label domain ending like, and customers purchase domain names one level below that, like While not always technically accurate, it is common to refer to all registry-controlled domain endings as TLDs.

For a detailed explanation of TLDs, see Top-level domain.

Unicode and Punycode

Within the Domain Name System, for historical reasons, domain names are stored in ASCII. International domain names (IDNs) that are normally written in Unicode are compressed into ASCII with a scheme called Punycode.

Domain names expressed in Punycode start with the characters "xn--". For example, an IDN representation of the Unicode is example.xn--qxam in Punycode.

The Punycode and Unicode versions of a domain name are equivalent and used in different contexts. For example, the name of each Registration resource ends in the Punycode version of the corresponding domain name. On the other hand, in user-facing contexts, the domain name is generally displayed in Unicode for ease of use.


A registry is a database that contains registrant information for second-level DNS domains (, beneath a given domain ending or TLD (.com). A registry can control any domain ending, and can allow you to register domains under that domain ending. For example, and

A registry operator is an organization that maintains the administrative data for one or more top-level or lower-level DNS 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, a corporation responsible for managing functions that maintain the core infrastructure of the internet. For more details, see ICANN.


A registrar is an organization that manages the registration of domain names for one or more of the DNS registries. A registrar acts as an interface between a registrant (owner) and a registry (database of domains). Registrars sell domain names, provide registration services, and offer other value-added services applicable to domains. For details about registrars, see Domain name registrars.

For Cloud Domains, Google is the registrar.

The InterNIC directory of accredited registrars provides an alphabetical list of accredited registrars.


A registrant is the registered name holder of a DNS domain. A registrant holds the rights to the domain for the duration of the registration period.

Because a domain's registration can be renewed indefinitely (up to 10 years at a time), a registrant is often considered the owner of the domain.


Registration is the process through which a registrant registers a domain with a DNS registrar. A registrant can register a domain for a period from 1 to 10 years. When the registration period expires, the registrant can renew or extend the registration. The registrant must provide contact information to the registrar for inclusion in the WHOIS database.

To register a domain using Cloud Domains, see Register a domain. To edit your domain registration settings, see Edit registrations.

WHOIS database

The WHOIS database stores information about DNS domains, such as the following:

  • Registration contact information for registrant, administrator, and technical contacts
  • The domain's registrar
  • Creation, update, and expiration dates

The WHOIS protocol, which is a query and response protocol used for querying databases that store details about registered domain users, is documented in RFC 3912. For details about WHOIS, see the ICANN WHOIS page. You can look up registered domain names and associated details on the ICANN WHOIS database.

DNS hosting provider

A DNS hosting provider is a company that maintains DNS name servers.

If you choose Google Domains or Cloud DNS as your DNS provider, then Google is your DNS hosting provider. If you are using custom name servers, then the company responsible for those name servers acts as your DNS hosting provider.

Cloud DNS

Cloud DNS is a high-performance and resilient DNS hosting provider that you can use with Cloud Domains to publish your domain names to the global DNS name space. For detailed information about Cloud DNS concepts and key terminology, see the Cloud DNS overview.

Resource records

Resource records provide DNS-based information about the hardware and software components that point to and support your domain (hosts, name servers, web servers, email servers, and so on). For detailed information about resource records, see Records.

For a list of record types supported by Cloud DNS, see Supported record types.

Name servers

Name servers identify the location of your domain on the internet. A DNS name server stores DNS records for a domain name and responds with answers to queries against its database. For a detailed explanation of name servers, see Name server.

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