What is a DNS server ? What is the use of a DNS server ?

DNS server translates the human-readable domain names (www.google.com) into machine-readable IP addresses (142.250.70.196) which is required for navigating the internet. We can consider its like a Internet Phone Book.

How it works ?

• When you type a URL in the browser, your device sends the query to DNS server.
• The DNS server, known as recursive resolver, it checks in its cache if it has IP address for given domain name. Otherwise, it will searches for it by communicating with other DNS servers, including root name servers and authoritative name servers.
• Once it finds the IP address, it will be sent back to your device, then your browser connect to that website.

We can see the DNS server in windows using ipconfig command ipconfig /all

Wireless LAN adapter Wi-Fi:
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Intel(R) Wi-Fi 6 AX201 160MHz
   Physical Address. . . . . . . . . : XXXXXXXXXXXXXXXX
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   IPv6 Address. . . . . . . . . . . : XXXXXXXXXXXXXXXX
   Temporary IPv6 Address. . . . . . : XXXXXXXXXXXXXXXX
   Link-local IPv6 Address . . . . . : XXXXXXXXXXXXXXXX
   IPv4 Address. . . . . . . . . . . : 192.168.1.10(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : Friday, October 31, 2025 9:36:25 AM
   Lease Expires . . . . . . . . . . : Saturday, November 1, 2025 1:21:33 PM
   Default Gateway . . . . . . . . . : fe80::1%13
                                       192.168.1.1
   DHCP Server . . . . . . . . . . . : 192.168.1.1
   DHCPv6 IAID . . . . . . . . . . . : XXXXXXXXXXXXXXXX
   DHCPv6 Client DUID. . . . . . . . : XXXXXXXXXXXXXXXX
   DNS Servers . . . . . . . . . . . : XXXXXXXXXXXXXXXX
                                       XXXXXXXXXXXXXXXX
                                       192.168.1.1
   Primary WINS Server . . . . . . . : 192.168.1.1
   NetBIOS over Tcpip. . . . . . . . : Disabled

Note: Here, the 192.168.1.1 is my router IP address, which is also acting as my DNS server, DHCP server. We can also use the google public DNS server 8.8.8.8 (alternative: 8.8.4.4)