Module 1: What Is the Web?

Module objective

Understand what the web is, how it differs from the internet, and what happens when you open a page in your browser.

Simple explanation

Many people use the words "internet" and "web" as if they meant the same thing. In reality, they are two different things:

• The internet is the physical network — the cables, antennas, and satellites that connect computers around the world. It's the infrastructure, the road.
• The web is what travels on that road — the pages, websites, images, and videos you view with your browser (Chrome, Firefox, Safari...).

Put another way: the internet is the network of roads, and the web is the traffic flowing on them.

How does it work when you open a website?

When you type an address like www.example.com into your browser, here's what happens behind the scenes:

graph LR
    A["You type an address"] --> B["Your browser sends a request"]
    B --> C["The request travels across the internet"]
    C --> D["It reaches a remote computer (server)"]
    D --> E["The server prepares the page"]
    E --> F["The page travels back"]
    F --> G["Your browser displays it"]

1. You type an address (for example www.wikipedia.org)
2. Your browser sends a request across the internet
3. That request reaches a special computer called a server — a computer that's on 24/7 and whose job is to respond to requests
4. The server prepares the requested page
5. It sends the page back to your browser
6. Your browser displays the result on screen

All of this happens in a few tenths of a second.

Key terms to remember

A bit of history

The web was invented in 1989 by Tim Berners-Lee, a researcher at CERN in Switzerland. His idea: allow scientists to share documents by clicking on links that connect pages to each other. That's actually why it's called a "web" — because the pages are linked together like the threads of a spider's web.

Concrete example

Imagine you're looking for a chocolate cake recipe. You open Chrome and type the address of a cooking website. Within moments, the page appears with the recipe, photos, and a video. What you don't see: your browser sent a request to a server that might be thousands of miles away, that server prepared the page, and sent it back to your computer — all in less than a second.

Metaphor

Think of the web as a network of libraries connected by roads (the internet). When you want a book (a web page), you give the reference (the URL) to the librarian (the browser). The librarian sends a courier (the request) along the road (the internet) to the right library (the server). The librarian at that library finds the book, and the courier brings it back to you. All you have to do is open it and read.

Summary in 3 key points

1. The internet is the network (the roads), the web is what flows on it (the pages and websites)
2. When you open a website, your browser sends a request to a server, which sends back the page
3. The URL is the address of a page — it's how your browser knows where to go to find the information