How It Works

Every time you type a URL into your browser and press Enter, a series of steps happens behind the scenes. Understanding this process helps you reason about how your code reaches users.

Step 1: DNS Lookup. Your browser takes the domain name (like example.com) and asks a DNS server to translate it into an IP address (like 93.184.216.34). This is like looking up a phone number in a directory.

Step 2: TCP Connection. Your browser establishes a connection with the server at that IP address. They perform a "handshake" — a brief exchange that confirms both sides are ready to communicate.

Step 3: HTTP Request. Your browser sends an HTTP request — a structured message asking for a specific resource. A simple request looks like:

GET /index.html HTTP/1.1
Host: example.com

Step 4: Server Response. The web server processes the request and sends back an HTTP response containing the requested file, along with a status code:

• 200 OK — the file was found and returned

• 404 Not Found — the requested resource doesn't exist

• 500 Internal Server Error — something went wrong on the server

Step 5: Rendering. Your browser receives the HTML, parses it, fetches any additional resources (CSS, JavaScript, images), and renders the page on screen.

This request-response cycle is the foundation of everything on the web. Every click, every form submission, every API call follows this pattern.