# Using Node.js as a simple web server

Node.js comes with a built-in module called `http` that can be used to create a simple web server. Below is a basic example of how to create a simple HTTP server using Node.js:

```jsx
const http = require('http');

// Create a server object
const server = http.createServer((req, res) => {
  // Set the response header
  res.writeHead(200, {'Content-Type': 'text/plain'});

  // Send a response
  res.end('Hello, this is a simple Node.js web server!');
});

// Specify the port on which the server will listen
const port = 3000;

// Start the server and listen on the specified port
server.listen(port, () => {
  console.log(`Server running at <http://localhost>:${port}/`);
});
```

In this example:

- We import the `http` module.
- We create a server using `http.createServer()`. This function takes a callback function with `req` (request) and `res` (response) as parameters. Inside the callback, you handle the incoming request and send the response.
- We set the response header using `res.writeHead()` to indicate that the response is plain text.
- We send a simple text response using `res.end()`.
- We specify the port (in this case, 3000) on which the server will listen.
- We start the server with `server.listen()`.

Save the code in a file, for example, `server.js`, and run it using the following command in the terminal:

```bash
node server.js
```

Now, if you open your web browser and navigate to `http://localhost:3000/`, you should see the message "Hello, this is a simple Node.js web server!".

This is a very basic example, and in a real-world scenario, you might want to use frameworks like Express.js for more features and better organization of your code. However, for a simple use case, the built-in `http` module is sufficient.