Domain Name System

Domain Name System (DNS) is a general-purpose distributed, replicated, data query service chiefly used on the Internet for translating s into Internet addresses. The style of hostname used on the Internet is properly called a. DNS is defined in STD 13, RFC 1034, RFC 1035, RFC 1591.

Usage
DNS queries can be configured to use a sequence of s, based on the domains in the name being looked for, until a match is found. The name resolution client (e.g. Unix's gethostbyname library function) can be set to search for host information in the following order: first in the local, second in NIS and third in DNS. This sequencing of Naming Services is sometimes called "name service switching". Under, it is configured in the file /etc/nsswitch.conf. DNS can be queried interactively using the command.