What is Node.js: A Popular And Powerful JavaScript Runtime Environment Explained


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Key takeaways:

  • What is Node.js?
  • Why use Node.js instead of PHP/ASP?
  • How Node.js works?
  • Pros and cons of Node.js.

Node.js is a framework cum platform built over Chrome’s V8 JavaScript engine. It is suitable for developing network applications. It is fast, reliable, open-source, and diverse. Node.js runs on different platforms like Windows, Unix, Mac OS, Linux, etc. Since we derive it from JavaScript, so anyone knowing JS can shift to Node.js effortlessly. 

Why use Node.js instead of PHP/ASP?

Here is how PHP/ASP deals with a file request:

  1. Passes the task to the computer’s file system.
  2. Waits for the system to open up and read it.
  3. Sends the content to the client.
  4. Ready to handle the next file request.

Here is how Node.js deals with a file request:

  1. Passes the task to the computer’s file system.
  2. Ready to handle the next file request.
  3. As soon as the file system opens and reads the file, the server sends the content to the client.

So, this shows that Node.js eliminates the waiting time and continues with the next request. Hence, it is faster than PHP/ASP and suitable for server and desktop applications.

How Node.js works?

In contrast to the traditional methods, Node.js runs on a single-thread. It uses non-blocking I/O calls and allows them to support tens of thousands of concurrent connections held in an event loop. In simple terms, a new file request coming in is one kind of an event. The server then starts processing it. When there is blocking I/O operation, it does not wait until it completes instead; it registers a call-back function. 

The server then immediately starts to process another file request/event. When the I/O operation is finished, that is another kind of event, and the server will process it by executing the call-back as soon as it has time.So, going this way, the server creates no additional thread(s) or switch between thread(s). If you want to make full use of multiple hardware cores, you just start multiple instances of Node.js. So, this is how Node.js works.

Node Package Manager (NPM)

NPM is a library built by the Node.js community to solve the generic problems faced by the developers. NPM consists of packages that simplify the development process using Node.js.

Require Function

It has primarily three responsibilities:

  1. To load modules that come bundled with Node.js like the file system and HTTP.
  2. To load third-party libraries like Express and Mongoose.
  3. Let the users install their own files to modularize the project.

Node.js Modules

A Node.js module is basically a reusable piece of code. It does not affect other blocks of code. You can create your own module in Node.js and can use it as and when required. For convenience, Node.js comes with pre-installed modules. These further aids in server and back-end development.

Node.js Events

In simple terms, an event is something that has happened to our app and we can respond to it. In Node.js, there are two kinds of events.

  1. Custom events
  2. System events

Pros of Node.js

  • Scalability

This is one of the most contrasting features of Node.js. Node.js developers can scale the application in any direction. Moreover, you can also add additional resources to a single node during the vertical scaling of the app. 

  • Easy to learn

JavaScript is a popular and powerful programming language. Every developer possesses a good grasp of it. Since Node.js is based on it, anyone has knowledge of JS can shift to Node.js easily.

  • Node.js can be used as a single programming language

Developers can write server-side applications in Node.js without any other language. It makes the deployment of the web application smoother as every browser supports JS.

  • Large and active community 

Node.js possesses the support of extensive community support. This community is responsible for the smooth performance of Node.js.

Cons of Node.js

  • API is not stable

Node.js API suffers frequent changes and hence, it’s not stable.

  • Does not have a vast library support system 

JS does not possess a vast library support system which is common with other languages. This forces the developers to go with ordinary libraries for their tasks.

  • Asynchronous programming model

The developers find the model more difficult in comparison to the blocking I/O programming. Also, codes of asynchronous programming become clumsy at times.


So, all this proves that Node.js is more beneficial than being harmful to the developers. They base it on JS, and hence is easy to learn and implement.  Day by day, more and more organizations prefer for Node.js developers for front-end and back-end servers. 

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