Node.js - http module

// http module : leveraging Node.js networking and creating HTTP servers and processing HTTP requests.

// Import the http module
const http = require('http');

// Create a simple server
const server = http.createServer((req, res) => {  //callback function with request & response as the arguments
  res.end('Hello World');
});

/*
The req object contains all of the information about an HTTP request ingested by the server. It exposes information such as the HTTP method (GET, POST, etc.), the pathname, headers, body, and so on. The res object contains methods and properties pertaining to the generation of a response by the HTTP server. This object contains methods such as .setHeader() (sets HTTP headers on the response), .statusCode (set the status code of the response), and .end() (dispatches the response to the client who made the request).
*/

// Once the .createServer() method has instantiated the server, it must begin listening for connections.
server.listen(4001,() => {
const { address, port } = server.address();
  console.log(`Server is listening on: http://${address}:${port}`);
})