Glossary of Terms

What is a domain name?
Domain names are the familiar, easy-to-remember names you find on the Internet, such as "" They correspond to a series of numbers called Internet Protocol numbers (or IP addresses) that serve as routing addresses on the Internet. Imagine if people identified themselves by their phone numbers instead of their names. Domain names fill a similar purpose on the Internet and are much easier to remember than a series of numbers. Domain names identify a specific network location on the Internet. It is your identity on the Internet and provides you with an address that other Internet users can use to find you on the World Wide Web. Here are some domain names you might be familiar with: - .US Register - Linux Online Inc. - Microsoft Corporation - the Canadian Internet Registration Authority (CIRA) - Afilias, the .info registry - Neulevel, the .biz registry

What is an IP address?
Every computer on the Internet has a numeric address called an IP Address, which is used to identify the location of the computer. An example of an IP address is Each domain name replaces this string of numbers with an easy-to-remember domain name.

What is a DNS?
DNS stands for Domain Name Server (also referred to as Domain Name Service or Domain Name System). A DNS translates domain names into IP addresses. If someone wants to access your web site, the DNS translates the domain name into its corresponding IP address (a series of numbers) allowing the computer to locate your company's web server.

What is a URL?
URL stands for Universal Resource Locator and is a unique identifier for your web address containing your domain name. For example, No two web sites can have the same URL. Whoever registers a domain name first gets to use it in their URL.

What are the components of a domain name?

Top-Level domains: A top-level domain (TLD) refers to the suffix attached to Internet domain names. Common top-level domains used on the Internet are .com, .net, .org, .info, and .biz.
Country Code Top-Level Domains: Two letter top-level domains, such as .ca and .us are called country code top level domains (ccTLDs) and correspond to a country, territory or other geographic location.
Second-Level Domains: The body of a domain name is called the second-level domain. In, "us-register" represents a second-level domain within the top level domain of .com.
You can also put another word in front of the second level domain. For example, or In these examples the words "information" and "president" are called "host" names or a "sub-domains". You do not need to register a host or sub-domain with a registrar.
Third and Fourth-Level Domains: An example of a third-level domain is A fourth level domain would be IMPORTANT NOTE: .US-Register no longer offers third and fourth level domain names.
What kinds of domains are available?
We offer a variety of top level domains including the well-known .com, .net, and .org. and country-code domains, such as .ca and .us. In light of diminishing .com availability, seven new TLDS, .info, .biz, .pro, .name, .aero, .coop, and .museum, were approved to allow for a greater choice of domain extensions.

Each new TLD has a distinct purpose:

  • .INFO is the only unrestricted new TLD -- ideal for informational web sites. (now available!)
  • .BIZ is designed exclusively for business -- registrants must have a bona fide business. (now available!)
  • .NAME is for individuals, who want to register their legal names as e-mail and web addresses.
  • .PRO is geared to doctors, lawyers, and accountants and other professionals so they can register web addresses indicating their professional designation.
  • .AERO is restricted to members of the air transport industry and civil aviation sector.
  • .MUSEUM was created for the museum community so they can register web addresses that identify them as authentic museums.
  • .COOP is aimed to help cooperatives differentiate themselves from other types of businesses and organizations online.
What is ICANN?
Formed in October 1998, the Internet Corporation for Assigned Names and Numbers (ICANN) is a non-profit, private sector corporation recognized by the U.S. government as the entity to coordinate the technical management of the Internet's domain name system, the allocation of IP addresses, the assignment of protocol parameters, and the management of the root server system. ICANN is located at

What is a registrar?
The organization responsible for the actual registration of the domain name is known as the registrar.

What is a registrant?
The entity, organization, or individual listed as the legal holder of the domain name is known as the registrant.

What is an administrative contact?
The administrative contact is the person or organization authorized by the registrant to answer non-technical questions about the registrant's plans for using the domain name and the procedures for establishing sub-domains.

What is a billing contact?
The billing contact is the person or organization that will be invoiced for registrations and renewals of the domain name.

What is a technical contact?
The technical contact is the person or organization that maintains the domain name registrant's primary name server and resolves software, and database files. The technical contact keeps the name server running and interacts with technical people in other domains to solve problems that affect the domain name. An Internet Service Provider often performs this role. If the technical or billing contact information is missing from the Registration Agreement, it is presumed that the domain name registrant has authorized the administrative contact/agent to act as the technical contact.

Do I need all these contacts simply to register a domain name?
In many cases, a single person will be the sole contact for the domain acting as registrant, administrative, billing and technical contact.