DNS stands for Domain Name System.

It is used to associate names to IP addresses.

Much like a telephone book, it is much easier to remember a name instead of a number. For example, www.swst.com instead of 192.168.10.23. The added benefit is that the address can change and the result is transparent to the user.

DNS first appeared in 1984 and was designed by Paul Mockapetris of USC when the original hosts.txt file was too large for distribution and maintenance.