The Domain Name System is maintained by a distributed database system. This system uses a client-server model and has nodes called name servers. The domains and sub-domains have one authoritative DNS server showing information about that particular domain and the name servers of any of its subordinate domains.
How Do DNS Servers Work?
DNS servers involve anything that you do on the Internet. Even the mere act of sending e-mail or browsing through the Web involves DNS servers.
A DNS server can be any computer registered to join the DNS. This computer is then run with special networking software featuring a public IP address and a database of other network addresses and names for other hosts.
DNS servers convert human-readable addresses or domain names to computer-friendly addresses or IP addresses. But with so many domain names and counterpart IP addresses, this becomes a very difficult job for DNS servers. Each server is assigned with a unique address for it to execute this function properly.
This means each of these servers needs to communicate with each other. Private network protocols are used by each of the servers. There are also root servers holding the complete database of the Internet domain names and their IP addresses. As of today, there are 13 famous root servers employed by the Internet. Ten of these reside in the United States, one is found in Japan, another in London, England. The last is in Stockholm, Sweden.
DNS servers function as parts of a hierarchy. This means the whole system is distributed in order to reduce and manage the stress on the servers and to make things easier.
The top of the hierarchy is composed of the root servers. The 13 root servers distribute the database to the lower levels of the hierarchy. Hence, all other servers maintain only a piece of the database and are only able to function with that set of data. However, it makes things work a lot faster as the machines don’t have to go through too much information to find a domain name.
This kind of networking functions on a client/server architecture. The browser you use in your computer is a DNS client. If the server linked to the client receives a request that is not in its database (if it is too far from the area of operation or if it is a low-traffic website), it changes to a temporary client and issues the request to another server. The cycle goes on until the request is found.