General doubt

Node.js is JavaScript's version of a backend or server-side language. JavaScript is unique in that a majority of its syntax carries over to the backend. There are new concepts (such as dealing with the filesystem) that must be learned, but all the key JavaScript core is there. Other backend languages can handle all the same problems that Node does, but the convenience of Node to a JS programmer is that you are able to dive into the backend with the same language that you learned the frontend on. This helps you to really grasp the intricacies of the backend in a language you are familiar with because you aren't worried about the syntax mistakes of diving into a new language such as PHP, Ruby, Python, etc.. It is as good, if not better at handling backend tasks as those other languages in particular instances due to its non-blocking, asynchronous, event-driven nature, but like anything it depends on what it will be used for. It is really great for DIRT(data intensive real-time) applications for instance, but in instances where it isn't doing very many asynchronous tasks it might be overkill. That's where some of the other lightweight, backend languages shine.

Anytime Rohit. Here to help. Keep up the coding!