DNS

Short for Domain Name System or Domain Name Service, a DNS is an Internet or other network server that helps to point domain names or the hostname to their associated IP address that was introduced by Paul Mockapetris and Jon Postel in 1984. If a domain name is not found within the local database, the server may query other domain servers to obtain the address of a domain name.

For example, when a user is accessing the Computer Hope domain a user would enter the easy to remember domain: computerhope.com. When entered that domain name is looked up on a Domain Name System to translate that name into an IP address that can be better understood by computer, e.g. 69.72.169.241. Using that IP address the computers can then find the computer containing the Computer Hope web page and forward that information to your computer.

A DNS Record, also called a Resource Record, is the basic element in the DNS. Each record contains several pieces of information, including a record type, expiration time limit, a class, and type-specific data. There are a large number of record types, each describing the format of the data and an idea of the intended use of the record. When being sent over an IP network, all DNS records conform to a format specified in RFC 1035 (contains a detailed description of the domain system and protocol).

Without a server to resolve a domain name or the proper rights you'd have to know the IP address of each of the web pages or computers you wanted to access.

Also see: A record, CNAME, DNS hijacking, Domain, Domain namespace, Hosts file, MX record, Nameserver, Network definitions, Port, rDNS, SOA