You use domain name every time, you try access a web page on the internet or every time you try sending an email to someone. It is very important to understand why domain names are used. Basically all the computers on the internet have their IP address using which other computers access data on that computer. But, since IP address is made up of digits, it becomes very tedious for humans to remember each and every computer’s IP address. Therefore, domain names came into existence to make things easier for human being to remember web site addresses.
A domain name works as a substitute for a IP address of a computer. In order to find out which domain is substituted for which IP address, we need to record this information somewhere. This relationship between domain names and IP addresses is stored on domain name servers.
There are thousands of domain name servers on the internet. Each one is responsible for maintaining certain numbers of domain name information. Thus a domain name look up information is passed between these name servers until the one containing the information is reached and the mapped IP is found. Each domain name record requires two name servers: a primary name server and a secondary name server. If the primary name server is not found, then the request is sent to secondary name server.