Domain Name

A domain name (often simply called a domain) is an easy-to-remember name that’s associated with a physical IP address on the Internet. It’s the unique name that appears after the @ sign in email addresses, and after www. in web addresses. For instance, the domain name might translate to the physical address 198.102.434.8. Other examples of domain names are and Using a domain name to identify a location on the Internet rather than the numeric IP address makes it much easier to remember and type web addresses.

Anyone can purchase a domain name. You just go to a domain host or registrar, find a name no one else is using, and pay a small annual fee to own it.

When you sign up for Google enterprise services, you supply the domain name you want to use with your services. If must be a domain you own (or we'll help you purchase one) and we’ll ask you to verify ownership. To learn more, see Domains and web addresses.


A subdomain is a domain that's part of a larger domain. For example,,, and are all subdomains of the domain Domain owners can create subdomains to provide easy-to-remember addresses for web pages or services within their top-level domain.

Naked Domain

A naked domain is simply a domain address without the "www" prefix, such as (naked) instead of (non-naked). See also Enable your "naked" domain address.

Primary Domain

With Google enterprise services, your primary domain is the domain you used to sign up for your enterprise account. You can add other domains to your account later, but the primary domain is unique in that it's the only domain that can have custom web addresses or associated domain aliases. For details, see Choosing your primary domain.

Secondary Domain

In addition to your primary domain, you can add additional domains to your account to let users in those domains use your services, too. When you add a domain that has its own users, we refer to it as a secondary domain. For details, see Add users from another domain.

Domain Alias

A domain alias is a domain name that acts as an alias for another domain. You can add a domain to your account as a domain alias to give everyone in your primary domain another email address at the domain alias. Mail sent to either of a user's addresses arrives at the user's same Gmail inbox. For details, see Give users an address at another domain.

IP Address

An Internet Protocol (IP) address is a series of numbers that identifies the physical location of a particular device on the Internet network. An IP address looks something like this:

Since a domain name can have one or more associated IP addresses, Google Apps doesn't support email and web publishing configurations using IP addresses alone.

Domain Registrar

A domain registrar is a company that sells domain names that aren't yet owned and are therefore available for registration. Most of these companies also offer domain hosting.

Google is not a domain registrar, but we offer registration through domain host partners. This lets you purchase a domain name when you sign up for a Google enterprise account. If you purchase a domain while signing up for Google Apps, we automatically activate Gmail for the domain and create custom web addresses. If you sign up with a domain name you already own, you'll need to need to do these things yourself by changing DNS records at your domain host.

Domain Host

A domain host is a company that runs the DNS servers for your domain and manages its DNS records. These include MX records for setting up Gmail, CNAME records for creating web addresses, and more. Most domain hosts offer domain name registration, as well.

Google is not a domain host. So to modify your domain's DNS records, you must sign in to your domain's account at your domain host. If you're not sure who your host is, see Identify your domain host.

WHOIS Directory

The WHOIS directory is a public listing of domain names, and the people or organizations associated with each name.

As a privacy measure, some domain name owners prefer to have their personal information hidden from the WHOIS directory, just as you might want your personal telephone number to be unlisted in a local telephone book.

You can use the WHOIS directory to determine the owner of domain names and IP addresses. There are many free web-based directories available on the Internet. The information provided in the WHOIS directory includes a mailing address and a telephone number.