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About Domain Names

Now that you have a domain name, it's good to understand the basics of what domain names are and how they fit into the Domain Name System (DNS).

Click here to learn more about the various players in the Domain Name Industry.

The Domain Name System (DNS) helps you find your way around the Internet. Every computer on the Internet has a unique address. This address is a rather complicated string of numbers called "IP address" (IP stands for "Internet Protocol"). IP addresses are hard to remember so the DNS makes using the Internet easier by allowing a familiar string of letters (the "domain name") to be used instead of the arcane IP address.

Another feature of DNS names is their hierarchical structure. This is reflected in the anatomy of the domain name. For example, the domain name "" has three levels of hierarchy: "org" is the top-level, "icann" is the second-level, and "whois" is the third-level. Remarkably, there can be up to 128 levels!

As seen by users, each level of the hierarchy is separated by a dot. At each dot, management authority, that is, the ability to create, edit, or remove names within that level or below, can be assigned or delegated to another party. Continuing to use "" as an example:

  • The ICANN community sets the rules for creating, editing, or removing top-level domains;
  • The organization that operates the "org" top-level domain sets the rules for registering domain names within "org" (e.g., registration policy); and
  • The ICANN organization, which registered the "" name, sets the rules for domain names under "" and using those rules, creates the name "".

So, when you register a domain name, you are creating a new realm in the DNS and giving that realm a name, which is the domain name that you registered.

Within this new realm, you can do a number of things such as create the domain name for a website that uses the same domain name you registered, or a sub-domain name. For example, if you register the domain name "", you could create a website and host it at, or at, or at You could also set up an email address using your domain name such as

Your domain name is not the same thing as a website or a Uniform Resource Locator (URL). While some people assume that the creation of a domain name automatically means you have a website, what they don't understand is that a domain name is like a street address for getting postal mail: there still must be a building or post office box to receive letters or packages. You must purchase, find, or implement services like web hosting or email to make your Internet presence known by your domain name functional and accessible to others.


Domain Name System
Internationalized Domain Name ,IDN,"IDNs are domain names that include characters used in the local representation of languages that are not written with the twenty-six letters of the basic Latin alphabet ""a-z"". An IDN can contain Latin letters with diacritical marks, as required by many European languages, or may consist of characters from non-Latin scripts such as Arabic or Chinese. Many languages also use other types of digits than the European ""0-9"". The basic Latin alphabet together with the European-Arabic digits are, for the purpose of domain names, termed ""ASCII characters"" (ASCII = American Standard Code for Information Interchange). These are also included in the broader range of ""Unicode characters"" that provides the basis for IDNs. The ""hostname rule"" requires that all domain names of the type under consideration here are stored in the DNS using only the ASCII characters listed above, with the one further addition of the hyphen ""-"". The Unicode form of an IDN therefore requires special encoding before it is entered into the DNS. The following terminology is used when distinguishing between these forms: A domain name consists of a series of ""labels"" (separated by ""dots""). The ASCII form of an IDN label is termed an ""A-label"". All operations defined in the DNS protocol use A-labels exclusively. The Unicode form, which a user expects to be displayed, is termed a ""U-label"". The difference may be illustrated with the Hindi word for ""test"" — परीका — appearing here as a U-label would (in the Devanagari script). A special form of ""ASCII compatible encoding"" (abbreviated ACE) is applied to this to produce the corresponding A-label: xn--11b5bs1di. A domain name that only includes ASCII letters, digits, and hyphens is termed an ""LDH label"". Although the definitions of A-labels and LDH-labels overlap, a name consisting exclusively of LDH labels, such as"""" is not an IDN."