HTTP & HTTPS: How Data Travels on the Web

Lesson 4: HTTP & HTTPS

So far, you’ve learned:

How a browser finds a server
How DNS translates names into numbers

Now let’s understand how data actually travels between your browser and a server.

What Is HTTP?

HTTP stands for:

HyperText Transfer Protocol

A protocol is simply a set of rules.

HTTP defines:

How a browser asks for data
How a server responds
How both understand each other

Without HTTP, browsers and servers wouldn’t know how to talk.

A Simple HTTP Conversation

Think of HTTP like a conversation:

Browser:

“Please send me the homepage.”

Server:

“Here is the page.”

That’s it.
Simple, direct, and fast.

What Gets Sent Using HTTP?

HTTP is used to send:

Web pages
Images
Videos
Form data
API responses

Almost everything you see on the web travels using HTTP or HTTPS.

The Problem with HTTP

HTTP has one big weakness:

❌ Data is sent in plain text

That means:

Anyone intercepting the data can read it
Passwords can be stolen
Information can be modified

This is dangerous.

Enter HTTPS

HTTPS is the secure version of HTTP.

The S stands for Secure.

HTTPS uses encryption, which means:

Data is scrambled before being sent
Only the browser and server can read it
Attackers see only random characters

How HTTPS Protects You

With HTTPS:

Passwords stay private
Personal data is protected
Websites can be trusted more easily

This is why modern browsers show:

🔒 A lock icon for HTTPS
⚠️ Warnings for HTTP websites

Does HTTPS Change How the Web Works?

No.

The steps remain the same:

Browser finds server (DNS)
Browser sends request
Server sends response

HTTPS just makes the communication safe.

Reflection Question

Think carefully:

Why do you think browsers warn users before opening an HTTP website?

Lesson Summary

HTTP defines how browsers and servers communicate
HTTP sends data in plain text
HTTPS encrypts data for safety
Secure communication is essential on the modern web

➡️ Next Lesson: What Happens After the Page Loads? (HTML, CSS & JavaScript)