[ glossary ]



The Domain Name System (DNS) is a distributed Internet directory service. DNS can store data of different kinds, but most frequently it's used for performing "mapping" between domain names and IP addresses and to control Internet email delivery.

Software providing DNS functionality has two parts:

  • DNS server
  • client library (now part of all modern operating systems).
In most cases, nothing needs to be installed or configured on the user side.

How DNS Works

Typically, as with all client-server systems, a client issues a request for data to a DNS server and the DNS server responds with data. Information the DNS server responds with can originate from the same DNS server or it can be obtained from another DNS server. (This property explains why DNS is "distributed". To avoid being too technical, we will not go into specifics here)