Domain name

Domain name (도메인 이름) means an identification string which makes users recognize the Internet Protocol (IP) address, only accessible by the computers and information communication facilities, with ease under the Act on the Internet Address Resources (인터넷주소자원에 관한 법률, hereinafter referred to as the "Internet Address Resources Act") as amended on June 9, 2009.

Domain names are formed by the rules and procedures of the Domain Name System (DNS). Domain names are used in various networking contexts and application-specific naming and addressing purposes. Domain names are organized in subordinate levels (subdomains) of the DNS root domain, which is nameless. The first-level set of domain names are the top-level domains (TLDs), including the generic top-level domains (gTLDs), such as the prominent domains com, net and org, and the country code top-level domains (ccTLDs).

Below these top-level domains in the DNS hierarchy are the second-level and third-level domain names that are typically open for reservation by end-users who wish to connect local area networks to the Internet, create other publicly accessible Internet resources or run web sites. The registration of these domain names is usually administered by domain name registrars who sell their services to the public.

Key words
domain name, Internet Protocol, Internet Corporation for Assigned Names and Numbers (ICANN), Korea Internet & Security Agency (KISA)

Purpose
Domain names serve as humanly-memorable names for Internet participants. A domain name represents an Internet Protocol (IP) resource. Individual Internet host computers use domain names as host identifiers, or hostnames. Hostnames are the leaf labels in the domain name system usually without further subordinate domain name space. Hostnames appear as a component in Uniform Resource Locators (URLs) for Internet resources such as web sites (e.g., koreanlii.or.kr). Domain names are also used as simple identification labels to indicate ownership or control of a resource.

An important function of domain names is to provide easily recognizable and memorizable names to numerically addressed Internet resources. This abstraction allows any resource to be moved to a different physical location in the address topology of the network, globally or locally in an intranet. Such a move usually requires changing the IP address of a resource and the corresponding translation of this IP address to and from its domain name. As for the History of Domain names, see Wikipedia.

Legal nature
Domain names are often referred to variously as trademark (상표), company name (상호), business mark (영업표지) or electronic mark in the Cyberspace (가상공간의 전자표지). Domain names may evolve to various kind of business assets depending on how they are actually used, whatever domain names are treated of the licensing relation, contractual right, property right, etc.

Though domain name registrants are frequently treated domain owners, domain name registration with a registrar does not confer any legal ownership or right of the domain name, but only an exclusive right of use. In the long run, the use of domain names in commerce may subject them to trademark law. Accordingly the enforcement of the [exclusive right to use] domain names is possible and effective subject to Article 251 of the Civil Execution Act.

Registry and registrars usually charge an annual fee for the service of delegating a domain name to a user and providing a default set of name servers. Often, this transaction is termed a sale or lease of the domain name, and the registrant may sometimes be called an "owner", but no such legal relationship is actually associated with the transaction, only the exclusive right to use the domain name. More correctly, authorized users are known as "registrants" or as "domain holders".

Domain name system
Today, the Internet Corporation for Assigned Names and Numbers (ICANN) manages the top-level development and architecture of the Internet domain name space. It authorizes domain name registrars, through which domain names may be registered and reassigned. The hierarchical domain name system, organized into zones, each served by domain name servers. The domain name space consists of a tree of domain names. Each node in the tree holds information associated with the domain name. The tree sub-divides into zones beginning at the DNS root zone.

Domain name syntax
A domain name consists of one or more parts, technically called labels, that are conventionally concatenated, and delimited by dots, such as example.com.

The right-most label conveys the top-level domain; for example, the domain name www.example.com belongs to the top-level domain com. The hierarchy of domains descends from the right to the left label in the name; each label to the left specifies a subdivision, or subdomain of the domain to the right. For example: the label example specifies a node example.com as a subdomain of the com domain, and www is a label to create www.example.com, a subdomain of example.com. This tree of labels may consist of 127 levels. Each label may contain from 1 to 63 octets. The empty label is reserved for the root node. The full domain name may not exceed a total length of 255 characters. In practice, some domain registries may have shorter limits.

A hostname is a domain name that has at least one associated IP address. For example, the domain names www.example.com and example.com are also hostnames, whereas the com domain is not. However, other top-level domains, particularly country code top-level domains, may indeed have an IP address, and if so, they are also hostnames.

Hostnames impose restrictions on the characters allowed in the corresponding domain name. A valid hostname is also a valid domain name, but a valid domain name may not necessarily be valid as a hostname.

Top-level domains
The top-level domains such as .com and .net and .org are the highest level of domain names of the Internet. A top-level domain is also called a TLD. Top-level domains form the DNS root zone of the hierarchical Domain Name System. Every domain name ends in a top-level or first-level domain label.

When the Domain Name System was devised, in the 1980s, the domain name space was divided into two main groups of domains. The country code top-level domains (ccTLD) were primarily based on the 250 two-character territory codes of ISO-3166 country abbreviations. In addition, a group of eight generic top-level domains (gTLD) was implemented which represented a set of categories of names and multi-organizations. These are the domains of gov[ernment], edu[cation], com[mercial], mil[itary], org[anisations], net[work], int[ernational] and arpa. In 2000, seven more - biz, name, info, pro, museum, coop and aero - were added to gTLD. Again in 2005 and 2006, six more - jobs, travel, cat, mobi, tel, post, xxx and asia - were added totaling 23 gTLDs.

During the 32nd International ICANN Meeting in Paris in 2008, ICANN started a new process of TLD naming policy to take a "significant step forward on the introduction of new generic top-level domains." This program envisions the availability of many new or already proposed domains, as well a new application and implementation process. In 2009, the 36th International ICANN Meeting in Seoul resolved to adopt multi-language country code domains. Upon completing procedural works and DNS servers, the registration of '.한국' began in May 2011 exceeding 210 thousand '.한국' domain names at the end of 2011. So far, 20 countries have applied for 30 country code in their own language. For further information on the generic TLD, visit the ICANN website.

Second-level and lower level domains
Below the top-level domains in the domain name hierarchy are the second-level domain (SLD) names. These are the names directly to the left of .com, .kr and other top-level domains. As an example, in the domain kdb.co.kr, co is the second-level domain.

Next are third-level domains, which are written immediately to the left of a second-level domain. There can be fourth- and fifth-level domains, and so on, with virtually no limitation. An example of an operational domain name with four levels of domain labels is www.onepark.khu.ac.kr. The www preceding the domains is the host name of the World-Wide Web server. Each label is separated by a dot. 'onepark' is said to be a sub-domain of 'khu.ac.kr', and 'khu' a sub-domain of 'ac.kr'. Subdomain 'onepark' is a domain subordinate to its parent domain.

Second-level (or lower-level, depending on the established parent hierarchy) domain names are often created based on the name of a company (e.g., kdb.co.kr), product or service (e.g., naver.com). Below these levels, the next domain name component has been used to designate a particular host server. Therefore, ftp.khu.ac.kr is an FTP server, www.khu.ac.kr is a World Wide Web server, and mail.khu.ac.kr is an email server, each intended to perform only the implied function. The hierarchical DNS labels or components of domain names are separated in a fully qualified name by the full stop (dot).

Internationalized domain names
The character set allowed in the DNS is based on ASCII and does not allow the representation of names and words of many languages in their native scripts or alphabets. As explained above, ICANN approved the Internationalized domain name (IDNA) system, which maps Unicode strings used in application user interfaces into the valid DNS character set by an encoding called "Punycode". KISA and many other registries have adopted IDNA.

History
The first commercial Internet domain name, in the TLD .com, was registered on 15 March 1985 in the name symbolics.com by Symbolics Inc., a computer systems firm in Cambridge, Massachusetts. At first, the registration and allotment were managed by the Internet Assigned Numbers Authority (IANA), and finally by ICANN, non-profit organization. In December 2009 there were 192 million domain names.

In Korea, ccTLD was introduced for the first time in 1986 by a scholar (KAIST 전길남 교수), then administered by an academic association (한국학술망협의회) in 1991, and transferred to KRNIC (한국인터넷정보센터) in 1993, and finally in 2002 co-managed by one registry (KISA) and 31 registrars (도메인이름 등록대행자). Since 2004, all the domain names-related works and disputes have been regulated by the Act on the Internet Address Resources.

Administration
The right to use a domain name is delegated by domain name registrars, which are accredited by the ICANN, the organization charged with overseeing the name and number systems of the Internet. In addition to ICANN, each TLD is maintained and serviced technically by an administrative organization operating a registry. A registry is responsible for maintaining the database of names registered within the TLD it administers. The registry receives registration information from each domain name registrar authorized to assign names in the corresponding TLD and publishes the information using a special service, the whois protocol.

ICANN publishes the complete list of TLD registries and domain name registrars. Registrant information associated with domain names is maintained in an online database accessible with the WHOIS service. For most of the 250 country code top-level domains (ccTLDs), the domain registries maintain the WHOIS (Registrant, name servers, expiration dates, etc.) information.

Some domain name registries, often called network information centers (NIC), also function as registrars to end-users. The major generic top-level domain registries, such as for the COM, NET, ORG, INFO domains and others, use a registry-registrar model consisting of hundreds of domain name registrars (see lists at ICANN or VeriSign). In this method of management, the registry only manages the domain name database and the relationship with the registrars. The registrants (users of a domain name) are customers of the registrar, in some cases through additional layers of resellers.

Domain name regulation
The domain name system is governed by the following laws and regulations:
 * Act on the Internet Address Resources (인터넷주소자원에 관한 법률)
 * Enforcement Decree of the Act (동법 시행령)
 * Domain Name Management Framework (도메인이름관리준칙)
 * Internet Address Dispute Mediation Rule (인터넷주소분쟁조정세칙)
 * Unfair Competition Prevention and Trade Secret Protection Act (부정경쟁방지 및 영업비밀보호에 관한 법률)
 * Trademark Act (상표법)
 * Commercal Act (상법)

Domain name dispute resolution
In line with the global trend and the Uniform Domain Name Dispute Resolution Policy, disputes related with domain names are settled by alternative dispute resolution and court litigation. See the Domain name dispute resolution. See the Domain name dispute.
 * Alternative dispute resolution
 * Court litigation