Beginner 8 lessons · 4 hours

Lesson 1: What is the Web?

Understanding how the internet works before writing your first line of code.

How the Web Works

The World Wide Web is a system of interlinked documents and resources accessed via the internet. When you type a URL into your browser, here's what happens:

DNS Lookup: Your browser translates the domain name (like a2zlessons.com) into an IP address
HTTP Request: Your browser sends a request to the server at that IP address
Server Response: The server sends back HTML, CSS, and JavaScript files
Rendering: Your browser assembles these files into the page you see

The Three Languages of the Web

Every website is built with three core technologies:

HTML (HyperText Markup Language) — The structure and content of a page
CSS (Cascading Style Sheets) — The visual styling and layout
JavaScript — The behavior and interactivity

Think of it like building a house: HTML is the walls and rooms, CSS is the paint and furniture, and JavaScript is the electricity and plumbing.

Your First HTML

Here's the simplest possible web page:

      HTML
<!DOCTYPE html>
<html lang="en">
<head>
  <title>My First Page</title>
</head>
<body>
  <h1>Hello, World!</h1>
  <p>This is my first web page.</p>
</body>
</html>
    

Every HTML document starts with <!DOCTYPE html> to tell the browser it's an HTML5 document. The <html> element wraps everything, <head> contains metadata, and <body> contains what you see on screen.

Tools You'll Need

To follow along with this course, you'll need:

A text editor — We recommend Visual Studio Code (free)
A web browser — Chrome, Firefox, or Edge with developer tools
Curiosity and willingness to experiment!

Quick Quiz: Check Your Understanding

Which technology controls the visual appearance of a web page?

HTML

CSS

JavaScript

SQL

Lesson 2: HTML Basics