This is a list of common terms that you'll encounter when managing a domain. Click a term below to jump to the description of the term, and its practical use with Google Apps.
Since registrars, hosts, and record configurations vary, this is a basic guide to DNS.
DNS
Domain Name
Domain Registrar
Top Level Domain
Second-level Domain
Third-level Domain
Domain Host
A Record
NS Record
MX Record
CNAME Record
IP Address
Custom URLs
Domain Alias
WHOIS directory
DNS
DNS stands for Domain Name System. This system is in place to organize and identify domains. Essentially, DNS provides a name for a domain's one or more IP addresses. For instance, the domain name wolf.example.com might translate to 198.102.434.8. This makes it much easier to remember URLs and email addresses.
DNS is also used to find out where to deliver email for a particular address. This is done with MX Records.
You need to have a registered domain name to use Google Apps for Your Domain.
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Domain Name
Domain names are easy-to-remember names (URLs and email addresses) that are associated with one or more IP addresses. Since a web page is defined by its URL, the page can move to a different IP address without affecting visitors.
Example: www.singlespeed.com
The whole domain name can not exceed a total length of 255 characters, but some registries have shorter limits.
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Domain Registrar
Domain registrars sell Internet domain names (ex. blueshirt.com or organicfood.org ). Most of these companies offer a hosting service in addition to registration.
If your domain registrar is separate from your domain host, you'll need to add the host's name servers to your registrar's account. For example, if you purchase a domain name from namecheap.com (which offers domain registration) and host your domain with DynDNS (which offers domain hosting), you'll add the name servers of DynDNS (ns1.mydyndns.org and ns2.mydyndns.org) to your account with namecheap.com.
Google Apps for Your Domain offers domain registration with a select group of domain registration partners. This allows you to purchase a domain name and sign up for Google Apps at the same time. If you purchase a domain name while signing up, Google will auto-configure services for your domain so that you won't need to manually configure MX and CNAME records.
If you purchased your domain name before signing up for Google Apps, visit our list of domain hosts (some of which are also domain registrars) that have instructions for modifying MX records in our Help Center.
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Top Level Domain
Top-level domains are the last part of a domain name - the letters after the last period. Some examples are: biz com org edu us ca fr de travel local es pl
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Second-level Domain
Second-level domains are directly below top-level domains. Some current examples are:
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Third-level Domain
Third-level domains are also known as subdomains and CNAMEs. In a URL, the subdomain is written before the domain name. Here's some examples:
To set up web publishing with Google Apps for Your Domain, you'll need to pick a subdomain as your web publishing address.
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Domain Host
Domain hosts run DNS servers for your domain. This includes A records, MX records, and CNAME records. Most domain hosts offer domain name registration as well.
Since Google Apps for Your Domain is not a domain host, you'll need to modify your DNS records with your domain host to set up email and web publishing. Click here if you don't know which company is hosting your domain.
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A Record
A records (also known as host records) are the central records of DNS. These records link a domain, or subdomain, to an IP address.
A records and IP addresses do not necessarily match on a one-to-one basis. Many A records correspond to a single IP address, where one machine can serve many web sites. Alternatively, a single A record may correspond to many IP addresses. This can facilitate fault tolerance and load distribution, and allows a site to move its physical location.
Google Apps for Your Domain does not support IP addresses alone. Instead of using A records, you can set up email and web publishing by modifying your MX and CNAME records with your domain host.
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NS Record
Name server records determine which servers will communicate DNS information for a domain. Two NS records must be defined for each domain. Generally, you will have a primary and a secondary name server record - NS records are updated with your domain registrar and will take 24-72 hours to take effect.
If your domain registrar is separate from your domain host, your host will provide two name servers that you can use to update your NS records with your registrar.
If you're not sure who is hosting your domain, you can perform a free NS Lookup. Here's how:
- Visit Google.com.
- Search for NS lookup.
- Select a search result.
- Type your domain name into the tool.
- Select NS records or Any records for your query.
- Click Look it up.
Example result (showing that name-services.com is the domain host for mightydinosaur.com):
mightydinosaur.com nameserver = dns1.name-services.com.
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MX Record
Mail Exchange records direct email to servers for a domain, and are listed in order of priority. If mail can't be delivered using the first priority record, the second priority record is used, and so on.
To set up email with Google Apps for Your Domain, you need to configure the MX records with your domain host using Google's server information.
If you'd like to check the status of your MX records, you can perform a free MX lookup. Here's how:
Example result (showing that email for
mightydinosaur.com is directed to
Google):
mightydinosaur.com mail exchanger = 10 aspmx.l.google.com.
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CNAME Record
Canonical name records are aliases for A records. For each CNAME record, you can choose an alias and a host.
To set up web publishing with Google Apps, you can pick an address for your web pages. The third-level domain of the address is the alias andghs.google.com is the host.
If you'd like to check the status of your CNAME record for web publishing, you can perform a free CNAME lookup. Here's how:
- Visit Google.com.
- Search for NS lookup.
- Select a search result from the list.
- Type your web publishing address in to the field.
- Select CNAME record if it's not the default search query.
- Click Submit, or Lookup.
Example result (showing that the subdomain of
start.mightydinosaur.com is pointing to
ghs.google.com):
DNS Lookup (CNAME) for start.mightydinosaur.com. Items Returned: 1
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IP Address
Internet Protocol addresses are unique numbers that allow devices to locate information on a network.
Since a domain name may have one or more associated IP addresses, Google Apps for Your Domain doesn't support email and web publishing configuration using IP addresses alone.
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Custom URLs
Custom URLs, or short URLs, make using the Internet easier. A custom URL allows you and your users to access the login page for services at your domain with a simple, easy-to-remember address. With Google Apps for Your Domain, your custom URLs will follow this format:
http://[customize this section].your_domain.com
Instead of asking your users to visit http://www.google.com/calendar/a/your_domain.com to log in to their calendars, you can create a short, custom URL. Learn more
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Domain Alias
Domain name aliases are additional domain names associated with your primary domain. With Google Apps for Your Domain, you can add a domain alias that receives mail and delivers it to mailboxes at your primary domain.
Some common uses:
WHOIS directory
The WHOIS directory is a public listing of domain names, and people or organizations associated with each domain name.
As a privacy measure, some domain name owners prefer to have their personal information hidden from the WHOIS directory. This is similar to the way someone may want his/her personal telephone number unlisted in a local telephone book.
The WHOIS directory is used 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.
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