The DNS is a distributed system, meaning that only the 13 root servers contain the complete database of names and addresses. All other DNS servers are installed at lower levels of the hierarchy and maintain only certain pieces of the overall database.
Most lower level DNS servers are owned by businesses or Internet Service Providers (ISPs). For example, Google maintains various DNS servers around the world that manage the google.com, google.co.uk, and other domains. Your ISP like hathway,Tata,Airtel etc. also maintains DNS servers as part of your Internet connection setup. Continue reading