DNS and domains
How the internet finds websites
⏱ Est. ~5 min
01 · Read
Every website lives on a server, and every server has an IP address — a number like 142.250.80.46. That's the server's real address, like a street address for a building.
But nobody wants to remember numbers. Imagine telling a friend: "Check out my website at 142.250.80.46!" Instead we use domain names like google.com or github.com — human-friendly and easy to remember.
The system that translates domain names into IP addresses is called DNS (Domain Name System). It's the internet's phone book.
💡 Picture thisDNS is like the contacts app on your phone. You don't remember your friends' phone numbers — you tap their name and the phone looks up the number for you. DNS works the same way: your browser says "I want google.com," DNS looks up the number (IP address), and the browser connects.
Key points
- Every server has an IP address (like 142.250.80.46)
- A domain name (like google.com) is a human-friendly alias for an IP address
- DNS (Domain Name System) translates domain names into IP addresses
- Every time you visit any website, a DNS lookup happens automatically
02 · Step-through
Here's what happens every time you type a URL into your browser — it only takes milliseconds, but there are several steps.
1. 1. You type example.com
You type a domain name into the browser's address bar and press Enter. At this point, the browser doesn't actually know where example.com lives — it only has a name, not an address.
2. 2. The browser asks DNS
Your browser sends a request to a DNS server: "What's the IP address of example.com?" DNS servers are maintained by ISPs and companies like Google (8.8.8.8) and Cloudflare (1.1.1.1).
3. 3. DNS returns the IP address
The DNS server looks up the record for example.com and returns an IP address, like 93.184.216.34. Now the browser knows which server to contact.
4. 4. The browser connects to that IP address
The browser uses the IP address to open a direct connection to the server. It sends an HTTP request asking for the website's contents.
5. 5. The server sends the website back
The server receives the request and sends back HTML, CSS, JavaScript, and images. The browser assembles these files and displays the complete web page. The whole process takes less than a second.
03 · Quiz
What does DNS stand for, and what does it do?
- Digital Network Service — provides internet connection
- Data Network Security — protects websites from being hacked
- Dynamic Node Server — runs websites
- Domain Name System — translates domain names into IP addresses
04 · Fill in the blank
DNS translates domain names into _____ addresses.
Other lessons in this chapter
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