What is DNS?

DNS (Domain Name System) is a hierarchical network distributed database system which provides to the Internet users a supplementary service (implemented with the help of computers — DNS servers with the special software installed) on automatic translation of queries in user-friendly text format (e.g., www.test.ru) into the computer numerical IP address (e.g., 123.123.123.123) needed for the purpose of locating the required resource.

Most commonly, DNS hierarchy is presented in the form of a tree structure. Root domain "." is at the bottom of the tree, which is followed by TLD (top level domains).

No IP addresses are assigned to the top level domains. They are intended for creation on their basis (in their zones) of second-level domains with subsequent assignment of IP addresses to them.