Google IT Solutions: What is DNS

Monday, 16 June 2014

What is DNS

Domain Name Service (D.N.S)

The DNS (Domain Name Service) is a standard technology for managing the names of Websites and other Internet domains. DNS technology allows you to type names into your Web browser like ( and your computer to automatically resolve that address on the Internet. A key element of the DNS is a worldwide collection of DNS servers.

DNS server is any computer registered to join the Domain Name System. A DNS server runs special purpose networking features public IP addresses and contains a database of network names and addresses for other Internet hosts.

DNS Root Server

DNS servers communicate with each other using private network protocols. All DNS servers are organized in a hierarchy. At the top level of the hierarchy, so-called root servers store the complete database of Internet domain names and their corresponding IP addresses.

DNS Hierarchy

The DNS is a distributed system, meaning that only the 13 root servers contain the complete database of domain names and IP addresses. All other DNS servers are installed at lower levels of the hierarchy and maintain only certain pieces of the overall database.
Lower level DNS servers are owned by businesses or ISP’s. For example, yahoo maintains various DNS servers around the world that manage the, and other domains. Your ISP also maintains DNS servers as part of your Internet connection setup.
DNS networking is based on the Client/Server architecture. Your Web browser functions as a DNS client and issues requests to your Internet provider's DNS servers when navigating between Web sites.
When a DNS server receives a request not in its database, it temporarily transforms from a server to a DNS client. The server automatically passes that request to another DNS server or up to the next higher level in the DNS hierarchy as needed. Eventually the request arrives at a server that has the matching name and IP address in its database and the response flows back through the chain of DNS servers to your client.

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