root server
Root servers are the central servers of the Domain NameSystem(DNS). They form the starting point of the hierarchically structured DNS system and manage information about the root domain. This includes the Top Level Domain( TLD) with the geographical Country Code Top Level Domain( ccTLD) and the Generic Top Level Domains( gTLD).
The root server knows the name server for the top- level domain, which in turn knows the address of the name server of the next hierarchy level, the second level domain( SLD). This in turn knows the next higher name server and so on until the complete domain name is converted into an IP address.
There are currently 34 root servers worldwide, which are operated by government organizations and all contain the same data that is regularly updated. The different root servers are identifiable by their own letter codes.