So, TypeScript is a superset of JavaScript, right? Let's see what that actually means by following these steps:

1. Create a new file called hello-world.ts:

You can do it from within VS Code:

As you can see, VS Code directly recognizes TypeScript files:

2. Now add the following code to your newly created file:

var hello = "Hello world";

function say(something) {
 console.log(something);
}

say(hello);

Now let's do a silly thing: let's ask Node (our JavaScript interpreter) to execute our TypeScript code:

$ node hello-world.ts 

The output will be as follows:

That worked? Well, as you have probably guessed, this first example only contains JavaScript, which is why node doesn't have any issue.