Starting from the end, the domain name is divided into a “TLD (Top-Level Domain)” preceded by a “SLD (Second-Level Domain).” The domains
are separated by a “. (Dot),” with the highest level domain placed at the
end of the domain name in descending order to the left.
The top-level domain is represented as a two-character country abbreviation. The second-level domain is an “organization domain” that describes
the type of organization that holds the domain name. In Japan, it is customary to use the organization domain, but usage of third-level and lower
domains depends on the country. A domain that is to the left of the secondlevel domain is called a “sub-domain.” The front of the domain name is
appended with WWW, or in the case of a large organization, it is appended
with a character string that distinguishes the group or other sub-organization.
Domain name
* * * .co.jp
Type of Country
Name of
organization organization
Organization types
exclusive to Japan
Example
co
General corporation
jp
Japan
ac
University, research institute
kr
Korea
go
Government agency
uk
United Kingdom
ne
Network services provider
None for United States
or
Other organization
* Domains such as .com (for
commercial organizations)
and .org (for non-profit
organizations) are used
according to the type of
organization.
Example: ***.com
Example
E-mail address
* * @* * * .co.jp
User name
Domain name
User ** who belongs to ***.co.jp.
The new operating rules for JP domains that use a domain name ending
with “jp” are referred to as the “generic JP domain” system. Under the
previous system for JP domains, second-level domains that describe the
type of organization (such as “co” or “ne”) were restricted to the organization types decided by JPNIC. Under the generic JP domain system, secondlevel domains are now available to general users and open to registration
such as registering an organization name. In addition, where the previous
system only allowed one organization to register one domain name in principle, the new system enables organizations to acquire any number of domain names. The generic JP domain system also opens up the use of domain names with Japanese characters, and the ability to transfer domain
names.
(3)DNS server
A “DNS server” is a server with DNS functions. A DNS server provides
services for translating domain name requests from clients into IP addresses.
DNS servers make it possible to view Web pages or send e-mail without
the user having to know the IP address.
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