What Is the Internet?

🎯 By the end of this lesson, you'll know: ➺ What the internet actually is — in the simplest way possible ➺ How data travels from one device to another ➺ What happens step by step when you open a website ➺ Key words every web developer needs to know

📚 Websites Books stored on those shelves — content waiting to be read.

🗄️ Servers The shelves themselves — powerful computers that hold and send the books.

📱 Your device The visitor who walks in and asks for a specific book.

🌐 The Internet The library building itself — the system that connects all the shelves and all the visitors together.

One-line definition: the internet is a giant network of computers connected around the world so they can send and receive information with each other.

The Internet Road System 🌊 Big Highways — Under the Ocean Huge cables lie at the bottom of the sea, connecting countries to each other. These are the main motorways. Incredibly fast. They carry enormous amounts of data between continents — Australia to the US, Europe to Asia, all of it. ――――――――――――――――――――――――――――― 🏙️ City Roads — Inside Your Country Smaller cables run under streets and into buildings, carrying the internet from those ocean cables to your city and neighbourhood. ――――――――――――――――――――――――――――― 🏠 Your Street — The Last Step A cable comes into your home or office. Your WiFi router takes that cable signal and spreads it wirelessly so your phone and laptop can connect without a wire.

WiFi is only the last tiny step of a very long journey. Most of the internet travels through physical cables — including ones sitting at the bottom of the ocean.

Ocean cables → City cables → Building cable → WiFi router → Your device

🙋 Client The device that asks for something. Your phone, your laptop, your tablet — anything you use to browse.

🏭 Server The computer that has the answer. Facebook's computers, Google's computers, YouTube's computers — sitting in massive buildings called data centres, running 24/7.

Real Example: Opening Facebook You (Client): Type facebook.com in your browser and press Enter. ⬇ Your request: "Hey Facebook server — send me your homepage." ⬇ Facebook (Server): Receives your request and prepares the page. ⬇ Facebook sends back: All the HTML, images, and data for your feed. ⬇ Your browser: Receives everything and shows you the Facebook feed. 📱

That entire journey — your request leaving your device, travelling to a server potentially thousands of kilometres away, and the page arriving back — takes less than one second.

https://www.facebook.com/login

https:// Protocol — the "language" used to communicate. The S stands for Secure. Almost all websites use HTTPS today.

www Subdomain — a section of the website. Mostly optional these days.

facebook Domain name — the website's actual name. This is what you register and pay for when you want a website.

.com Extension — the type of website. .org = organisation, .edu = education, country codes like .uk or .au also exist.

/login Path — which specific page inside the website you want. Like asking for a specific room inside a building.

A URL works the same way as a postal address — each part narrows it down further. https:// How to get there (delivery method) facebook.com The building name (which website) /login Which room inside the building

🌐 The Internet The road system — the physical infrastructure of cables and connections.

🕸️ The Web (WWW) Just one service that runs on top of the internet. Websites and web pages — that's the web.

📧 Email and apps Other services that also use the internet — but they're not "the web."

The internet is the roads. The web is one type of vehicle using those roads. Email, WhatsApp, and Spotify are other vehicles on the same roads.

You type google.com and press Enter Step 1 — DNS Lookup Your computer asks: "What is the IP address of google.com?" DNS (Domain Name System) is like the internet's phone book. It converts "google.com" into a number like 142.250.190.46 — the real address that computers actually understand. ――――――――――――――――――――――――――――― Step 2 — Connection Your computer connects to Google's server at that IP address. Like dialling a phone number — a connection line opens between your device and Google's server. ――――――――――――――――――――――――――――― Step 3 — HTTP Request Your browser sends a request: "Please send me your homepage." This is called an HTTP Request — a formal message asking for specific data. ――――――――――――――――――――――――――――― Step 4 — Server Responds Google's server sends back the files for the homepage. Three types of files arrive: HTML (structure), CSS (style), JavaScript (behaviour). You'll be working with all three in this course. ――――――――――――――――――――――――――――― Step 5 — Browser Builds the Page Your browser reads those files and draws the page on your screen. This is called "rendering" — turning code files into the visual page you actually see and interact with.

HTML, CSS, and JavaScript are the three files that arrive every time a page loads. Learning to write those files is exactly what this course teaches you.

Internet The global network of connected computers.

Client Your device — the one that asks for things.

Server A powerful computer that stores and sends data back to clients.

URL A web address — like https://google.com. Every page has one.

DNS The internet's phone book — converts website names into IP addresses.

IP Address A unique number that identifies every device on the internet — like 142.250.190.46. You won't write these by hand, but you'll see them mentioned often as you go deeper.

HTTP / HTTPS The communication language used between client and server. The S means the connection is encrypted and secure.

Browser The app that reads web files and shows you the finished page — Chrome, Firefox, Safari, Edge.

Bandwidth How much data can travel through your connection per second — the width of your internet pipe. This one becomes more relevant when you start optimising websites for speed. Park it for now.

You don't need to memorize these today. As you keep building, these words will become natural. Think of this as your first introduction — not a test.

⟢ Question 1 What is the difference between a Client and a Server? Give a real example of each.

⟢ Question 2 In the URL https://youtube.com/watch — what does each part mean?

⟢ Question 3 What does DNS do? Explain it using the phone book analogy.

⟢ Question 4 Next time you open a website today — think through the 5 steps happening in the background. Which step do you find most interesting and why?