DNS stands for Domain Name System
(DNS) handles mapping between human readable hostnames, and IP addresses, which computers use. You can think of DNS as a giant telephone directory.
While people prefer to reference computers by a name, computers address each other by number. On a
network, that number is 32 bits long for IPv4 (that’s a number between 0 and 4 billion) and 128 bits long for IPv6 (that’s a number between 0 and 340 billion billion billion billion, which is a seriously large number).
Another important feature of DNS is that it makes host information available all over the Internet. DNS provides a means of retrieving information remotely from anywhere on the network.
More than that, DNS lets you distribute the management of host information among many sites and organizations.