Domain Name System

DOMAIN NAME SYSTEM

Domain Name System is just like a phone-book in world of Internet. In phone-book there is a list of Contact-names & Contact-numbers. You can search for any number of your friend in the phone-book.
Just like phone-book, Domain Name System also contains a DNS table which is a list of Domain names aliases for a IP address. So what the Domain name is ?
Domain Name is the name of your website, domain name is the address from where users can access your website. For example - www.example.com is a domain name.
And What is IP address?
Internet Protocol Address is numerical label assigned to every device which is connected to Internet. For example - 172.167.54.1

How it works?

Servers (Machines) have resources which user can access through web browser. Web browser interact through IP addresses. So, every time user ask for a web page by typing domain name, domain name converts to it's corresponding IP address of server. Fetches the resource and display it to user in Web browser. Every Server on the Internet have their own IP address. Therefore, through DNS we can get the IP address of server.

There are 4 types of DNS server involving in loading a page:

1. Local DNS Server : These are the DNS server which get the client's queries to find a particular server of the resource which client wants. They are designed to satisfy the client's DNS query.

These are just like a librarian who is asked to find a book.

2. Root DNS Server : These are the DNS server which first converts the human readable host name into IP address and refers to TLD name server. For example - In order to find a book they are just like an index of different racks in a library.

3. TLD name server : Top Level Domain Name Server are the DNS server which specify the particular type of domain like .com, .org, .edu etc. For example - In library they refer to a specific rack where the book is placed.

4. Authoritative Name server : It is the last stop in the name server query. These the final destination where the address of the domain name is placed. For example - these are like the dictionary of a specific rack in the library, which then send to browser(client) in order to fetch resources. 

After Getting the IP address of hosting server now Web Browser(Client's Machine) can directly contact with Hosting Server and ask for resources.

You can gather information about any domain name through the website: whois . For ex -