We Use A User Friendly Name To Access A Webpage. How Does A Server Translates A Domain Name In To IP Address To Make It Computer Readable And Be Able To Send Us Back The Required Information?

The translation or resolution of a fully qualified domain name into its IP address takes place using the hierarchy of special computer machines called Domain Name Servers. A DNS server is a server on the network that maintains a database/table that contains the list of domain names and their corresponding IP addresses. The name servers for TLDs are also called Root Name Servers.

There is a program called 'Resolver' built into the browser, which sends the request for resolution of the domain name to the machine called Local Name Server. Local name server then contacts the root name server, which looks into its database and where possible provides the IP address of the name server below in the Hierarchy. Hence in a similar number of steps the fully qualified domain name is completely translated into the IP address of the web server where the requested web page is stored.

The process of name resolution has been explained below:
For example if a client requests ecom.cs.vu.edu, then the request is directed toward the Local Name Server. Now the local name server sends the request to the Root Name Server (The root name server has all the root names saved in it like edu, com, org etc). The Root Name Server sends the IP address of vu.edu back to the Local Name Server. Now Local Name Server follows the IP address of vu.edu and VU server will tell it CS IP address. And when Local Name Server follows the address of CS server it will have access on "ecom" which is saved in CS name server.

The user friendly name is called the domain name. InterNic is a world wide company which keeps the records of all the domain names and their IP addresses. This database is maintained by InterNic and is used by ISPs from all over the world.

When a user types a domain name in web browser then this information is sent to ISP (Internet service provider). The ISP keeps a copy of the database maintained by the InterNic of all the web addresses. ISP send back the IP address of the domain name back to the browser and browser then sends request for the content directly to that IP address.

If ISP fails to get the record of that particular domain name then it requests to InterNic to get the IP address. Further more all ISP updates their database after a specific time.These whole process is maintained by the DNS server of the ISPs. DNS stands for Domain Name Server. The responsibility of a DNS server is to convert the domain names into IP addresses.

When we register a domain name by any company they want approx 72 hours to make work it correct. In these 72 hours all the ISPs of the world updates its records from InterNic.