You type:

https://example.com 

You press Enter.

A moment later, the webpage appears.

But what actually happened between those two moments? 🤔

Let's break it down.

1️⃣ The Browser Checks the URL

Your browser first parses the URL.

For:

https://example.com 

we have:

https:// → Protocol example.com → Domain 

The protocol tells the browser how it should communicate with the server.

2️⃣ DNS Lookup

Your computer needs to find the IP address associated with:

example.com 

That's where DNS (Domain Name System) comes in.

Conceptually:

example.com ↓ DNS ↓ IP Address 

Instead of remembering an IP address, we can use a human-readable domain name.

3️⃣ A Connection Is Established

Once the browser knows the destination, it needs to communicate with the server.

For HTTPS traffic, this involves establishing a secure connection using TLS.

Depending on the protocol and network conditions, the underlying transport can involve TCP or QUIC/HTTP/3.

4️⃣ The Browser Sends a Request

The browser sends a request asking the server for the resource.

A simplified HTTP request might look like:

GET / HTTP/1.1 Host: example.com 

The server receives the request and processes it.

5️⃣ The Server Responds

The server sends a response.

For example:

HTTP/1.1 200 OK Content-Type: text/html 

The response contains the requested resource or information about what happened.

6️⃣ The Browser Builds the Page

The browser receives the HTML and begins processing it.

It may then request additional resources such as:

HTML ↓ CSS ↓ JavaScript ↓ Images ↓ Fonts ↓ Other resources 

The browser parses these resources and eventually renders the webpage you see.

🔎 The Full Journey

A simplified version looks like:

You enter a URL ↓ Browser parses URL ↓ DNS resolution ↓ Connection established ↓ TLS negotiation (HTTPS) ↓ HTTP request ↓ Web server ↓ HTTP response ↓ Browser processes resources ↓ Webpage appears 

And all of this can happen incredibly quickly.

🧪 CyberGround Challenge

Now it's your turn.

Open your browser's Developer Tools → Network tab.

Visit a website you are authorized to inspect.

Look at the first request.

Try to find:

🔹 Request URL
🔹 Request method
🔹 Status code
🔹 Response headers
🔹 Request headers
🔹 Remote address
🔹 Timing information

Then answer:

What was the first request your browser made?

What HTTP status code did you receive?

How many additional resources were loaded?

Don't worry if you don't understand everything yet.

That's exactly what CyberGround is for.

🧠 Question for the Ground

If DNS converts:

example.com → IP address 

what happens if DNS completely fails?

Drop your answer below. 👇

Learn. Investigate. Build. Defend.