What is TypeScript?

Relax. We'll talk through this in plain words — no textbook voice.

TypeScript is an open-source programming language created by Microsoft. It's a superset of JavaScript, meaning all JavaScript code is valid TypeScript code. TypeScript adds features like static types, classes, and interfaces on top of JavaScript.

typescript

// This is TypeScript code
let message: string = "Hello, TypeScript!";

// It compiles down to plain JavaScript
// let message = "Hello, TypeScript!";

console.log(message);

You should see

Key Takeaway: TypeScript adds type safety and modern features on top of JavaScript, then compiles down to plain JavaScript that browsers understand.