Otherwise, here’s a quick step-by-step explanation of how the JavaScript Event Loop works. 

• Push main() onto the call stack. 
• Push console.log onto the call stack. This then runs right away and gets popped. 
• Push Settimeout onto the stack. Settimeout is a Node API.
...

We have to do this, don’t we? 

A Node module is a reusable block of code whose existence does not accidentally impact other code. 

Node.js is a Javascript Runtime built on chrome’s V8 Javascript engine. It uses an event-driven, Non-Blocking I/O model that makes it lightweight and efficient. It can be anything ranging from Reading/Writing local files to making an Http request to an API. I/o takes time and hence blocks other f...

On the other hand, using a non-blocking request, you can initiate a data request for user2 without waiting for the response to the request for user1. You can initiate both requests in parallel. 

In the blocking method, user2's data request is not initiated until user1's data is printed to the screen. 

These are libraries built by the awesome community which will solve most of your generic problems. npm (Node package manager) has packages you can use in your apps to make your development faster and efficient.