`express` is a Node package that allows us to create web servers to host APIs that allow for http request, reponses and supports HTTP methods e.g GET and POST.

Install `express`

`npm install express`

An example of web server JavaScript code that will listen on a specific port and render "Hello, world" if the API address is visited.

```javascript

const express = require('express');

const app = express();

const port = 3000;

app.get('/', (request, response) => {

response.send(`Hello World!`);

});

app.listen(port, () => {

console.log(`Example app listening at http://localhost:${port}`);

});

To run the `express` web server

Edit the `package.json` to include a run script

```javascript

"scripts": {

"start": "node index.js"

}

Using the run script