How DNS Works

From Domain Name to IP Address - A Step-by-Step Journey

🏠 Think of DNS Like Finding Someone's Home Address

Imagine you want to visit your friend Sarah, but you only know her name and that she lives in "Springfield." You'd need to find her exact street address to get there. DNS works the same way - when you type "www.google.com" your computer needs to find the exact "internet address" (IP address) to connect to Google's servers.

Just like you might ask different people for directions (your neighbor, the post office, city hall), your computer asks different "internet directories" until it finds the right address!
🧑‍💻
User Types Domain Name
Technical: Browser receives "www.example.com"
Real Life: "I want to visit Sarah in Springfield"
You type a website name into your browser. Your computer knows this name, but needs to find the actual internet address (IP address) to connect.
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💭
Check Local Memory
Technical: Check local DNS cache
Real Life: "Do I already know Sarah's address?"
Your computer first checks if it remembers visiting this website recently. If it does, it uses that saved address and skips the rest!
Found in Cache!
Use saved address
Skip to website
Not in Cache
Need to ask around
Continue lookup
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🏢
Ask Your Internet Provider
Technical: Query ISP's DNS Resolver
Real Life: "Ask your helpful neighbor"
Your computer asks your internet provider (like Comcast or AT&T) if they know the address. They have a big directory and will help you find it.
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🌐
Ask the Root Directory
Technical: Query Root Name Server
Real Life: "Ask the main post office"
Your ISP asks the internet's main directory: "Where can I find .com websites?" The root server says "Go ask the .com department!"
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🏛️
Ask the .com Department
Technical: Query TLD (.com) Server
Real Life: "Ask Springfield's city hall"
The .com department says "I don't have the exact address, but I know who manages all 'example.com' addresses. Go ask them!"
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🎯
Ask the Website's Directory
Technical: Query Authoritative Name Server
Real Life: "Ask Sarah's apartment manager"
Finally! The website's own directory server says "Yes, www.example.com is located at IP address 192.168.1.1"
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🎉
Success! Connect to Website
Technical: Connect to IP address
Real Life: "You arrive at Sarah's house!"
The IP address gets passed back through the chain to your computer. Now you can connect to the website and see the page!
All this happens in milliseconds!