"DNS (Domain Name System) is the Internet service which connects different names together with machine numbers from the Internet and thereby makes it possible to send information to the right place on the net. DNS functions purely as a distributed database spread over many machines, the so-called name server machines.

For problem-free use of all Internet services, it is important that all machines in the local net which serve Internet users are correctly registered in DNS. It is consequently necessary in an organised operations cooperation between the responsible parts for local operations on the one end and the Internet provider on the other. "

Source: Wikipedia