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DNS Record Types Explained: A Beginner's Complete Guide

#webdev #dns #chaicode #networking

The 6 records that make websites, emails, and the internet work.

How does your browser know where google.com lives?

You type a name. Your computer needs an address. Something has to translate between the two.

That something is DNS (Domain Name System)—and it uses different types of records to answer different questions about a domain.

This article covers:

  • What DNS records are and why they exist
  • The 6 most important record types: NS, A, AAAA, CNAME, MX, TXT
  • Real-world analogies that make each record click
  • How all records work together for one website

Part 1: Why DNS Records Exist

The Problem

A single domain like example.com needs to do many things:

  • Host a website (where's the web server?)
  • Receive emails (where's the mail server?)
  • Prove ownership (how do I verify I own this domain?)
  • Handle subdomains (what about www, blog, api?)

One domain, many questions. Each question needs a different answer.

The Solution: Different Record Types

Think of DNS like a contact card:

┌─────────────────────────────────────────────────────────────────────────────┐
│                           CONTACT CARD ANALOGY                              │
└─────────────────────────────────────────────────────────────────────────────┘

    DNS Records are like fields on a contact card:

    ┌─────────────────────────────────────────┐
    │  EXAMPLE.COM                            │
    │  ─────────────────────────────────────  │
    │  Office Address:  192.168.1.1    (A)    │  ← Where to visit
    │  Alternate Name:  www → example  (CNAME)│  ← Also known as
    │  Mail Room:       mail.example   (MX)   │  ← Where to send mail
    │  Manager:         ns1.host.com   (NS)   │  ← Who handles inquiries
    │  Notes:           "Verified"     (TXT)  │  ← Extra information
    └─────────────────────────────────────────┘

    Different questions → Different record types!
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Part 2: The Big Picture

Before diving into each record, here's how they fit together:

┌─────────────────────────────────────────────────────────────────────────────┐
│                        HOW DNS RECORDS WORK TOGETHER                        │
└─────────────────────────────────────────────────────────────────────────────┘

    User types: example.com
         │
         ▼
    ┌─────────────────┐
    │  DNS RESOLVER   │  "Let me look up this domain..."
    └────────┬────────┘
             │
             │ Checks NS record: "Who manages example.com?"
             ▼
    ┌─────────────────┐
    │  NS RECORD      │ → ns1.dnshost.com (authoritative server)
    └────────┬────────┘
             │
             │ Asks authoritative server for A record
             ▼
    ┌─────────────────┐
    │  A RECORD       │ → 93.184.216.34 (website IP)
    └────────┬────────┘
             │
             ▼
    Browser connects to 93.184.216.34 → Website loads!

    ─────────────────────────────────────────────────────────────

    Meanwhile, for email:

    someone@example.com
         │
         ▼
    ┌─────────────────┐
    │  MX RECORD      │ → mail.example.com (mail server)
    └────────┬────────┘
             │
             ▼
    Email delivered to mail server!
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Now let's understand each record type.

Part 3: NS Record — Who's In Charge

The Question It Answers

"Who should I ask for information about this domain?"

The Analogy: Main Office Directory

Imagine you want to know about a company. First, you need to find their main office that handles all inquiries. That's what an NS record does.

NS = Name Server — The server that has the official information about a domain.

Example 

example.com.    IN    NS    ns1.dnshost.com.
example.com.    IN    NS    ns2.dnshost.com.
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This says: "For any questions about example.com, ask ns1.dnshost.com or ns2.dnshost.com."

Why NS Records Matter

Purpose Explanation
Delegation NS records tell the internet who controls a domain
Redundancy Multiple NS records = backup if one server is down
Domain Transfer Change NS records to move your domain to a new host

Real-World Use Case

When you buy a domain from GoDaddy but host on Cloudflare:

Before: example.com NS → ns1.godaddy.com
After:  example.com NS → ns1.cloudflare.com

Now Cloudflare controls your domain's DNS!
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Part 4: A Record — The Main Address

The Question It Answers

"What's the IPv4 address of this website?"

The Analogy: House Street Address

The A record is like a street address. When someone asks "Where does google.com live?", the A record gives the physical location (IP address).

A = Address — The IPv4 address where the domain points.

Example 

google.com.     IN    A    142.250.193.46
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This says: "google.com is at IP address 142.250.193.46"

Diagram: How A Records Work 

┌─────────────────────────────────────────────────────────────────────────────┐
│                         A RECORD MAPPING                                    │
└─────────────────────────────────────────────────────────────────────────────┘

    Human-readable               Machine-readable
    ┌──────────────┐             ┌────────────────┐
    │ google.com   │ ─── A ────► │ 142.250.193.46 │
    └──────────────┘             └────────────────┘

    ┌──────────────┐             ┌────────────────┐
    │ github.com   │ ─── A ────► │ 140.82.112.4   │
    └──────────────┘             └────────────────┘

    ┌──────────────┐             ┌────────────────┐
    │ example.com  │ ─── A ────► │ 93.184.216.34  │
    └──────────────┘             └────────────────┘

    The browser uses this IP to connect to the server!
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Multiple A Records = Load Balancing

Large sites can have multiple A records:

google.com.     IN    A    142.250.193.46
google.com.     IN    A    142.250.193.78
google.com.     IN    A    142.250.80.46
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DNS returns different IPs to different users, distributing traffic!

Part 5: AAAA Record — The Modern Address

The Question It Answers

"What's the IPv6 address of this website?"

The Analogy: Same House, New Postal Code Format

Remember IPv4 addresses like 142.250.193.46? We ran out of them.

IPv6 is the new format with virtually unlimited addresses. An AAAA record is like an A record, but for the new system.

AAAA = IPv6 Address (Four A's because IPv6 is 4x longer than IPv4)

Example 

google.com.     IN    AAAA    2607:f8b0:4004:800::200e
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Why IPv6?

IPv4 IPv6
~4.3 billion addresses 340 undecillion addresses
142.250.193.46 2607:f8b0:4004:800::200e
Running out Unlimited for practical purposes

Do You Need AAAA Records?

If Your Site... AAAA Record?
Is on a modern host Probably already set up
Needs to reach IPv6-only users Yes, required
Is internal/small Optional but good practice

Part 6: CNAME Record — The Nickname

The Question It Answers

"This name is an alias—what's the real name?"

The Analogy: "Also Known As"

Sometimes one name points to another name. Like how "Bill" is an alias for "William."

CNAME = Canonical Name — An alias from one domain name to another.

Example 

www.example.com.    IN    CNAME    example.com.
blog.example.com.   IN    CNAME    example.github.io.
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  • www.example.com → "Just use example.com"
  • blog.example.com → "Actually go to example.github.io"

Diagram: How CNAME Works 

┌─────────────────────────────────────────────────────────────────────────────┐
│                        CNAME POINTING TO ANOTHER NAME                       │
└─────────────────────────────────────────────────────────────────────────────┘

    User visits: www.example.com
         │
         ▼
    ┌─────────────────┐
    │  CNAME Record   │  www.example.com → example.com
    └────────┬────────┘
             │ (Follow the alias)
             ▼
    ┌─────────────────┐
    │  A Record       │  example.com → 93.184.216.34
    └────────┬────────┘
             │
             ▼
    Browser connects to 93.184.216.34

    ─────────────────────────────────────────────────────────────

    CNAME is like a redirect: "Don't look here, look THERE"
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⚠️ Common Confusion: A vs CNAME

Record Type Points To Use When
A IP address (142.250.193.46) You know the exact IP
CNAME Another domain name (example.com) You want an alias

Key Rule: CNAME points to a NAME. A record points to an ADDRESS.

Another Rule: You can't use CNAME at the root domain (example.com). Use it only for subdomains (www.example.com, blog.example.com).

When to Use CNAME

Scenario Use CNAME?
www.example.com → example.com ✅ Yes
Hosting blog on GitHub Pages ✅ Yes (blog.example.com → user.github.io)
Root domain to IP ❌ No, use A record

Part 7: MX Record — Email Routing

The Question It Answers

"Where should emails for this domain go?"

The Analogy: Post Office

Imagine your domain is a building. Visitors go to the front door (A record). But mail goes to a separate post office (MX record).

MX = Mail Exchange — The server that handles email for a domain.

Example 

example.com.    IN    MX    10    mail.example.com.
example.com.    IN    MX    20    backup-mail.example.com.
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The Priority Number 

MX    10    mail.example.com.       ← Try this FIRST (lower = higher priority)
MX    20    backup-mail.example.com. ← Try this if first fails
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Lower number = Higher priority. Email servers try them in order.

Diagram: Email Routing with MX 

┌─────────────────────────────────────────────────────────────────────────────┐
│                        MX RECORD EMAIL ROUTING                              │
└─────────────────────────────────────────────────────────────────────────────┘

    Email sent to: hello@example.com
         │
         ▼
    ┌─────────────────┐
    │ Sender's server │  "Where does example.com receive mail?"
    └────────┬────────┘
             │
             │ Looks up MX record
             ▼
    ┌─────────────────┐
    │  MX Record      │  Priority 10: mail.example.com
    │                 │  Priority 20: backup-mail.example.com
    └────────┬────────┘
             │
             │ Tries mail.example.com first
             ▼
    ┌─────────────────┐
    │  Mail Server    │  Email delivered!
    └─────────────────┘
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⚠️ Common Confusion: NS vs MX

Record Purpose Controls
NS Who manages DNS for the domain DNS queries
MX Who receives email for the domain Email delivery

NS is about DNS control. MX is about email delivery.

Real-World MX Setup

Using Gmail for business email:

example.com.    IN    MX    1     ASPMX.L.GOOGLE.COM.
example.com.    IN    MX    5     ALT1.ASPMX.L.GOOGLE.COM.
example.com.    IN    MX    5     ALT2.ASPMX.L.GOOGLE.COM.
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Part 8: TXT Record — The Notes Field

The Question It Answers

"What extra information is associated with this domain?"

The Analogy: Sticky Notes

TXT records are like sticky notes attached to your domain. They hold text that proves ownership or provides security information.

TXT = Text — Any text data attached to a domain.

Example 

example.com.    IN    TXT    "v=spf1 include:_spf.google.com ~all"
example.com.    IN    TXT    "google-site-verification=abc123xyz"
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Common Uses

Use Case Example TXT Content
Domain Verification google-site-verification=abc123
SPF (Email Security) v=spf1 include:_spf.google.com ~all
DKIM (Email Signing) v=DKIM1; k=rsa; p=MIGf...
DMARC (Email Policy) v=DMARC1; p=reject

Domain Verification Example

When you add a domain to Google Search Console:

  1. Google gives you a code: google-site-verification=abc123xyz
  2. You add a TXT record: example.com TXT "google-site-verification=abc123xyz"
  3. Google checks for this record
  4. Ownership verified!

Why TXT Records Matter for Developers

Service Uses TXT For
Google Workspace Domain verification
SSL Certificates Domain control validation
Email Providers SPF, DKIM, DMARC
CDN Providers Ownership proof

Part 9: All Records Working Together

Let's see a complete DNS setup for a small website.

Scenario: Small Business Website

Domain: mybusiness.com
Needs:

  • Website hosted on a server
  • www subdomain working
  • Business email via Google Workspace
  • SSL certificate verification

Complete DNS Configuration 

┌─────────────────────────────────────────────────────────────────────────────┐
│                  COMPLETE DNS SETUP FOR mybusiness.com                      │
└─────────────────────────────────────────────────────────────────────────────┘

Record Type   Name           Value                          Purpose
─────────────────────────────────────────────────────────────────────────────

NS            mybusiness.com ns1.cloudflare.com.            DNS management
NS            mybusiness.com ns2.cloudflare.com.            (backup)

A             mybusiness.com 203.0.113.50                   Website server
AAAA          mybusiness.com 2001:db8::1                    IPv6 for website

CNAME         www            mybusiness.com                 www → root domain
CNAME         blog           mybusiness.github.io           Blog on GitHub

MX            mybusiness.com ASPMX.L.GOOGLE.COM.     (1)    Email via Gmail
MX            mybusiness.com ALT1.ASPMX.L.GOOGLE.COM.(5)    Backup mail

TXT           mybusiness.com "v=spf1 include:_spf.google.." Email security
TXT           mybusiness.com "google-site-verification=..." Ownership proof
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Diagram: How They Work Together 

┌─────────────────────────────────────────────────────────────────────────────┐
│               ONE DOMAIN, MULTIPLE RECORDS, DIFFERENT PURPOSES              │
└─────────────────────────────────────────────────────────────────────────────┘

                              mybusiness.com
                                    │
          ┌─────────────────────────┼─────────────────────────┐
          │                         │                         │
          ▼                         ▼                         ▼
    ┌───────────┐            ┌───────────┐            ┌───────────┐
    │    NS     │            │   A/AAAA  │            │    MX     │
    │  Records  │            │  Records  │            │  Records  │
    └─────┬─────┘            └─────┬─────┘            └─────┬─────┘
          │                        │                        │
          ▼                        ▼                        ▼
    Cloudflare               Web Server               Gmail Servers
    (controls DNS)           (203.0.113.50)          (handles email)

          │
          ▼
    ┌───────────┐
    │   CNAME   │  www.mybusiness.com → mybusiness.com
    │  Records  │  blog.mybusiness.com → github.io
    └───────────┘

          │
          ▼
    ┌───────────┐
    │    TXT    │  SPF for email security
    │  Records  │  Domain verification
    └───────────┘
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Part 10: Quick Reference

Record Types Summary

Record Purpose Points To Example
NS Who controls DNS Name server domain ns1.cloudflare.com
A Website address (IPv4) IP address 142.250.193.46
AAAA Website address (IPv6) IPv6 address 2607:f8b0:...
CNAME Alias/redirect Another domain name example.com
MX Email server Mail server domain + priority 10 mail.google.com
TXT Extra info Any text v=spf1 include:...

When to Use Each Record

I Want To... Use This Record
Point domain to a server A (or AAAA for IPv6)
Make www work CNAME (www → root)
Receive email MX
Verify domain ownership TXT
Change DNS provider NS
Create subdomain alias CNAME

Quick Commands to Check Records 

# Check A record
dig example.com A +short

# Check MX records
dig example.com MX +short

# Check NS records
dig example.com NS +short

# Check TXT records
dig example.com TXT +short

# Check all records
dig example.com ANY +short
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Conclusion

DNS records are the backbone of how the internet routes traffic.

Record One-Line Summary
NS "Who controls this domain's DNS"
A "The IPv4 address of this domain"
AAAA "The IPv6 address of this domain"
CNAME "This name is an alias for that name"
MX "Where emails should go"
TXT "Extra notes attached to the domain"

The key insight: Each record answers a different question. When you understand what question each record answers, DNS stops being mysterious.

Now you can confidently set up and debug DNS for any domain. Go make the internet work! 🌐

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