DNS를 아주 쉬운 말로 설명 (모두를 위해)

Source: Dev.to

If you’ve heard about DNS (Domain Name System) and want a basic overview of how it works, this guide explains it in simple terms.

How does your browser know where a website lives?

When you type a domain name, e.g.:

google.com

your browser needs to translate that name into an IP address because computers understand only numbers. DNS is the service that tells the browser, “google.com lives at this number.”

What DNS Really Is (No Technical Jargon)

Think of DNS as the phonebook of the internet.

• Phone analogy: You save contacts like Mom, Dad, or a friend, but calls are made using phone numbers.
• Internet analogy: You type a website name, DNS finds the corresponding IP number, and the browser connects to that address.

Without DNS you’d have to remember numbers such as 142.250.182.14 to reach Google.

Why DNS Records Exist

DNS records are small pieces of information that answer specific questions, such as:

• Where is this website?
• Who is responsible for this domain?
• Where should email be delivered?
• Is this domain trusted?

Different record types each have a clear purpose.

NS Record – Who Is Responsible for This Website?

Imagine an apartment building: you go to the main office for information, not random tenants. The NS (Name Server) record is that main office. It tells the internet which server to ask for all information about the domain.

A Record – Where Is the Website?

The A record maps a domain name to an IPv4 address (the “house number”).

example.com → 93.128.332.34

Your browser retrieves this number, connects directly to the server, and loads the website.

AAAA Record – Same Job, Newer System

The AAAA record does the same thing as an A record but stores an IPv6 address (the newer address format). Both A and AAAA records tell where the website lives.

CNAME Record – Another Name for the Same Place

A CNAME (Canonical Name) record points one domain name to another.

www.example.com → example.com

In other words, www.example.com is just an alias for example.com.

MX Record – How Emails Know Where to Go

When an email is sent to user@example.com, the MX (Mail Exchange) record tells the internet which mail server should receive the message. Without an MX record, email delivery fails.

TXT Record – Extra Notes and Proof

TXT records are like sticky notes attached to a domain. They’re used for:

• Proving domain ownership
• Enhancing email security (e.g., SPF, DKIM)
• Verifying services (e.g., Google Search Console)

These records don’t affect website content but operate behind the scenes.

How Everything Works Together (A Simple Story)

1. Browser looks up the NS record to find out who manages the domain.
2. The DNS server returns the A/AAAA record with the website’s IP address.
3. If www is used, a CNAME may redirect to the main name.
4. For email, the MX record directs messages to the correct mail server.
5. TXT records provide verification and security information.

All records cooperate like a team to make the internet function smoothly.

One Complete DNS Setup (Quick Overview)

NS    → Who manages the domain
A     → Website IPv4 address
AAAA  → Website IPv6 address
CNAME → Alias to another name
MX    → Email delivery server
TXT   → Verification and security data

Final Words

DNS may sound intimidating, but it’s essentially a system that matches names to the right places—just like a phonebook, a house address, and a post office. Understanding those analogies means you already understand DNS.