Domain Name System (DNS) – Explained Simply
Instead of remembering long numbers for every website, users
can simply type a name in the browser, and DNS finds the correct server in the
background. This process happens within seconds using a global network of DNS
servers.
Why DNS is Important
DNS makes the internet user-friendly by:
- Connecting
website names with their real server locations.
- Ensuring
data reaches the correct destination.
- Allowing
faster access through stored (cached) results.
How DNS Works (In Simple Terms)
- A user
enters a website address in the browser.
- The
browser asks a DNS server for the IP address.
- If the
DNS server does not already know the answer, it contacts other DNS
servers.
- Once
the IP is found, the browser connects to the correct server and loads the
website.
Main Parts of the DNS System
DNS is built using different layers of servers:
- Recursive
Resolver – First point of contact for the user.
- Root
Server – Directs the query to the correct domain type.
- TLD
Server – Handles domains like .com, .org, .in.
- Authoritative
Server – Stores the final answer.
DNS Caching
To improve speed, DNS stores previous results. If you visit
the same website again, the browser can load it faster without repeating the
full lookup process.
Without DNS, users would need to memorize IP addresses for
every website, making normal internet use almost impossible.
Essential DNS Records Everyone Should Know
1. A and AAAA Records – Address Records
These records link a domain name to the actual server.
- A
Record: Connects a domain to an IPv4 address (example: 192.168.1.1)
- AAAA
Record: Connects a domain to an IPv6 address (example: 2001:db8::1)
Why they are important:
These records tell the browser exactly where the website is hosted. Without
them, no website can be accessed.
2. CNAME Record – Alias Record
A CNAME record makes one domain behave like another domain.
Example:
If blog.mysite.com should show the same content as mysite.com, a CNAME record
is used.
Benefit:
If the main server IP changes, only one record needs updating, and all linked
domains will automatically work.
Common Use:
Used when connecting domains to external platforms like hosting services or
support systems.
3. MX Records – Mail Records
MX records define which mail server receives emails for a
domain.
- They
use priority values (such as 10, 20, 30).
- Lower
number = higher priority.
- If the
main server fails, the next one is used.
Important rule:
MX records always point to a domain name, not directly to an IP address.
Why it matters:
Incorrect MX records mean you will not receive any emails, even if your website
works fine.
4. TXT Records – Verification and Security Records
TXT records store text information in DNS and are widely
used for security and verification.
Main uses:
- Domain
verification – Proves ownership for services like email or analytics
tools.
- Email
protection – Used for SPF and DKIM to prevent fake emails being sent
from your domain.
These records help protect your domain from misuse and
improve email trust.
Summary Table
|
Record Type |
Points To |
Main Purpose |
|
A |
IPv4 Address |
Links domain to a server |
|
CNAME |
Another Domain Name |
Creates an alias for a domain |
|
MX |
Mail Server Domain |
Handles incoming emails |
|
TXT |
Text Data |
Verification and email security |



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