Domain names are the human-friendly forms of Internet addresses, and are commonly used to find web sites. For example, the domain name bip.sx is used to locate the Bureau for Intellectual Property's web site at http://www.bip.sx
The domain name system (DNS) is essentially a global addressing system. It is the way that domain names are located and translated into Internet Protocol (IP) addresses, and vice versa. A domain name such as bip.sx is a unique alias for an IP address (a number), which is an actual physical point on the Internet. IP Addresses are hard to remember. 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. So instead of typing 220.127.116.11, you can type www.internic.net. It is a "mnemonic" device that makes addresses easier to remember.
Top Level Domains
Every domain name around the world ends with a top-level domain (TLD); these are the 2 or more letters that come after the dot. There are currently two types of TLDs:
- generic top-level domain (gTLDs) such as .com, .mobi, and .info, and
- country code top-level domains (ccTLDs) such as .uk, .br, and .cn.
A gTLD or a ccTLD is managed by a registry operator, an organization that maintains the registry database, including the nameserver information for names registered in the TLD.
Country Code Level Domain (ccTLD)
A ccTLD is a country code top-level domain. These ccTLDs are administered independently by nationally designated registration authorities. There are currently 252 ccTLDs reflected in the database of the Internet Assigned Numbers Authority (IANA), for example:
- .sx for Sint Maarten,
- .ca for Canada,
- .jp for Japan,
- .eu for the European Union.
A listing of existing ccTLDs is available at http://www.iana.org/domains/root/db/.
Generic Top Level Domain (gTLD)
A gTLD is a generic top level domain. It is the top-level domain of an Internet address, for example:
- .aero (for the entire aviation community);
- .biz (for business purposes);
- .coop (for cooperatives);
- .info (unrestricted);
- .museum (for museums);
- .name (for personal names);
- .pro (for professionals).
ICANN is the global forum for developing policies for coordination of some of the Internet's core technical elements, including the domain-name system (DNS). ICANN operates on the basis of consensus, with affected stakeholders coming together to formulate coordination policies for the Internet's core technical elements in the public interest. The policies are then implemented by the agreement of the operators of the core elements, including gTLD registry operators and sponsors, ccTLD managers, regional Internet (IP address) registries, and root-nameserver operators.