Name server (nameserver) is combination of software program and hardware device which implements a name-service protocol. It maps a human-recognizable domain names to a system-internal, numeric identification.

The most widely used types of name servers are those of the Domain Name System (DNS). The most important function of the DNS servers is to translate (resolve) of domain names and hostnames into Internet Protocol (IP) addresses, which are the second principal Internet name space, used to identify and locate network device, server or computer on the Internet.

The Domain Name System is an Internet naming system that makes it possible to assign domain names to groups of Internet resources and users, independent of each entity’s physical location. Domain names are easier to remember than IP addresses such as 207.75.188.166 (IPv4) or 2001:db6:1f70::999:de8:7648:6e8 (IPv6). Internet users use domain names to recite meaningful Uniform Resource Locators (URLs) and e-mail addresses.

The Domain Name System distributes the responsibility of assigning domain names and mapping those names to IP addresses by designating name servers for each domain. Name servers are responsible for their particular domains. The are DNS distributed and fault tolerant. This makes possible for the WWW to avoid keeping everything in a single central register which has to be continually consulted and updated.

Domain Name System also stores information about the list of mail servers that accept email for web addresses. Domain Name System is a very important component of the Internet as we know it because it provides a distributed keyword-based redirection service.

Domain Names are web addresses, identification labels which defines an administrative autonomy, authority, or control in the Internet.

A Domain name is also hostname which identifies Internet Protocol (IP) resources such as web sites. Domain names are formed by the rules and procedures of the Domain Name System (DNS). They are used in various networking contexts and application-specific naming and addressing purposes. Domains 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 .COM, .NET and .ORG, and the country code Top-level domains (ccTLDs).

There are second-level and third-level domain names in the DNS hierarchy which are open for reservation by end-users as well.