Below the root, Internet resources are organized into a hierarchy of domains, administered by the respective registrars and domain name holders.A DNS name server is a server that stores the DNS records, such as address (A, AAAA) records, name server (NS) records, and mail exchanger (MX) records for a domain name (see also List of DNS record types) and responds with answers to queries against its database.
It translates an often humanly meaningful, text-based identifier to a system-internal, often numeric identification or addressing component.
This service is performed by the server in response to a service protocol request.
An example of a name server is the server component of the Domain Name System (DNS), one of the two principal namespaces of the Internet.
In addition, many home-networking routers implement caching resolvers to improve efficiency in the local network.
When you use Google Public DNS, you are changing your DNS "switchboard" operator from your ISP to Google Public DNS.