DNS (Domain Name Servers)
Domain name server or system is basically an Internet service that has the task to translate domain names into IP addresses. It is an interesting fact that the entire Internet runs on IP addresses and Domain names have been brought into reality only to help users to memorize them. Hence, For instance, when you type www.abc.com, it gets translated into something like 220.127.116.11 and then appears on your screen.
Another important fact about DNS is that it is an entire network. In situations where one DNS server fails to translate a specific domain name, it has the ease to request another one to do so. A series of DNS can be contacted within to find the correct, working IP address. With the advent of DNS in the web hosting environment, you need not to remember or keep your own address book of IP addresses. All you need to do is to connect through a domain name server, also called a DNS server or name server that maps domain names to IP addresses.
Components of DNS:
A Domain Name Server contains two primary components namely Nameserver and Resolver. Nameserver performs the important task of looking up the names. In case a Nameserver doesn’t find the requested information, it contacts another Nameserver immediately. It is however not required for every server to connect to other server.
Resolver not only runs contains a list of Nameservers but also used on the client machine to instigate the DNS lookup. In case a user changes the entities and ingredients of Nameservers, it should also be reflected and propagated to secondary Nameservers.