Introduction to JavaScript

JavaScript is one of the most important programming languages in the world. It is used to make websites interactive, dynamic, and intelligent. In this course, you will learn JavaScript step by step — from absolute beginner to building real projects.

What JavaScript Can Do

JavaScript allows you to respond to user actions like clicks and typing. It can change content on a page, validate forms, communicate with servers, and power complete web applications.

Every modern website you visit today uses JavaScript in one way or another. Learning it opens doors to frontend, backend, mobile apps, and even AI tools.

Your First JavaScript Example

Below is a simple example. When the button is clicked, JavaScript will run and show a message.

<button onclick="sayHello()">Click Me</button>

<script>
function sayHello() {
  alert("Welcome to JavaScript!");
}
</script>

What You Learned in This Lesson

In this lesson, you learned what JavaScript is, why it is important, and how JavaScript code can respond to user actions. This is the foundation for everything you will build next.