how DNS happening

first let see as flow:

      user----> DNS query initialization----> sub resolver [local machine]

example:
www.wikipedia.org.
here last [.] represent root
org represents TLD [Top level domain]
Wikipedia represents SLD [secondary level domain]
www represents Zone file

                root [name server]
                /         |       \
               /          |        \
              /           |         \
           .org           .com     .in
          [Name server]
           /
          /
         /
    Wikipedia [name server]
       /
      /
     /
 www ------> IP

zone file :
A -----> IPV4
AAAA----> IPV6
mx-------> mail

When your browser needs to resolve a domain (like www.wikipedia.org.), it doesn’t directly go to root servers first.

It usually goes to a DNS resolver provided by your ISP (Internet Service Provider).

Here’s the real-world flow:

1. You Type a Website www.wikipedia.org.
2. Browser Checks Cache

If not found → continue

1. Request Goes to ISP DNS Resolver

Your device sends the request to:
Your ISP’s DNS server

Example:

Airtel DNS
Jio DNS

This server is called a recursive resolver

1. ISP Resolver Checks Cache If it already knows → returns IP immediately If not → it starts querying:
2. ISP Contacts Root Server org[.]

“Where is www.wikipedia.org.?”

1. ISP Contacts TLD Server org.

“Where is www.wikipedia.org.?”
7.next it goes to SLD here it has the Ip address
where is www.wikipedia.org.

1. zone file is www it has IPV4 :A IPV6:AAAA MX: MAIL