Node.js is an open source, cross-platform runtime environment for developing server-side and networking applications. Node.js applications are written in JavaScript, and can be run within the Node.js runtime on OS X, Microsoft Windows, and Linux.

Node.js also provides a rich library of various JavaScript modules which simplifies the development of web applications using Node.js to a great extent.

Node.js = Runtime Environment + JavaScript Library

Features of Node.js

Here,given some features of Node.js below:

Asynchronous and Event Driven
All APIs of Node.js library are asynchronous, that is, non-blocking. It essentially means a Node.js based server never waits for an API to return data. The server moves to the next API after calling it and a notification mechanism of Events of Node.js helps the server to get a response from the previous API call.

Single Threaded but Highly Scalable
Node.js uses a single threaded model with event looping. Event mechanism helps the server to respond in a non-blocking way and makes the server highly scalable as opposed to traditional servers which create limited threads to handle requests. Node.js uses a single threaded program and the same program can provide service to a much larger number of requests than traditional servers like Apache HTTP Server.

Very Fast
Being built on Google Chrome’s V8 JavaScript Engine, Node.js library is very fast in code execution.

No Buffering
Node.js applications never buffer any data. These applications simply output the data in chunks.

The Positive and Negative Aspects of Node.js

pros of Node.js

1) Node.js offers an Easy Scalability

One of the key advantages of Node.js is that developers find it easy to scale the applications in horizontal as well as the vertical directions. The applications can be scaled in horizontal manner by the addition of additional nodes to the existing system.

Moreover, Node.js also offers you the option of adding extra resources to the single nodes during the vertical scaling of the application. So, it is highly scalable and provides better option than other JavaScript servers.

2) The Benefit of Fullstack JS
Node.js has been regarded as a full-stack JavaScript for serving both the client and the server-side applications.

Therefore, the advantage is that you don’t have to hire separate developers for backend as well as the front-end development. It saves both your valuable money and time.

3) Known for Offering High Performance
It has been mentioned earlier that Node.js interprets the JavaScript code via Google’s V8 JavaScript engine. This engine complies the JavaScript code directly into the machine code. This makes it easier and faster to implement the code in a effective manner.

The speed of the code execution also enhanced by runtime environment as it supports the non-blocking I/O operations.

4) The Advantage of Caching
The open-source runtime environment of the Node.js also provides the facility of caching single modules. Whenever there is any request for the first module, it gets cached in the application memory.

The developers don’t have to re-execute the codes as caching allows applications to load the web pages faster and responds more swiftly to the user.

5) Handles the Requests Simultaneously
Since the Node.js is providing the option of non-blocking I/O systems, it relatively helps you to process several requests concurrently.

The system can handle the concurrent request handling efficiently better than others including Ruby or Python. The incoming requests get lined up and are executed quickly and systematically.

Drawbacks of Node.js

1) Application Programming Interface (API) is Not Stable
One of the key problems that most of the developers encounter is the Application Programming Interface (API) keeps on changing at frequent intervals and does not remain stable.

At times, a new API appears having a number of backwards-incompatible changes. As a result the developers are forced to make changes in the accessible code bases to match the compatibility with the latest version of the Node.js API.

2) Does not have a Strong Library Support System
The JavaScript does not have a well equipped and robust library system in comparison to other programming languages.

The result is that the users are forced to take the support of common library for executing various tasks such as Object-Relational Mapping (ORM), processing of the images, handling database operations, and XML parsing etc.

3) Asynchronous Programming Model
If you want to make the applications more scalable, the necessary requisite is adoption of the asynchronous programming model.

However, many developers may find this programming model to be more difficult in comparison to the linear blocking I/O programming.

Another con of the asynchronous programming is the codes tend to become clumsy and the programmers have to depend on the nested calls.