Node.js is a cross-platform environment and library for running JavaScript applications which is used to create networking and server-side applications.
Our Node.js tutorial includes all topics of Node.js such as Node.js installation on windows and linux, REPL, package manager, callbacks, event loop, os, path, query string, cryptography, debugger, URL, DNS, Net, UDP, process, child processes, buffers, streams, file systems, global objects, web modules etc. There are also given Node.js interview questions to help you better understand the Node.js technology.

What is Node.js

Node.js is a cross-platform runtime environment and library for running JavaScript applications outside the browser. It is used for creating server-side and networking web applications. It is open source and free to use. It can be downloaded from this link https://nodejs.org/en/
Many of the basic modules of Node.js are written in JavaScript. Node.js is mostly used to run real-time server applications.
The definition given by its official documentation is as follows:
?Node.js is a platform built on Chrome’s JavaScript runtime for easily building fast and scalable network applications. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.?
Node.js also provides a rich library of various JavaScript modules to simplify the development of web applications.
1. Node.js = Runtime Environment + JavaScript Library

Different parts of Node.js

The following diagram specifies some important parts of Node.js:

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Features of Node.js

Following is a list of some important features of Node.js that makes it the first choice of software architects.
1. Extremely fast: Node.js is built on Google Chrome’s V8 JavaScript Engine, so its library is very fast in code execution.
2. I/O is Asynchronous and Event Driven: All APIs of Node.js library are asynchronous i.e. non-blocking. So 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. It is also a reason that it is very fast.
3. Single threaded: Node.js follows a single threaded model with event looping.
4. Highly Scalable: Node.js is highly scalable because event mechanism helps the server to respond in a non-blocking way.
5. No buffering: Node.js cuts down the overall processing time while uploading audio and video files. Node.js applications never buffer any data. These applications simply output the data in chunks.
6. Open source: Node.js has an open source community which has produced many excellent modules to add additional capabilities to Node.js applications.
7. License: Node.js is released under the MIT license.

Prerequisite

Before learning Node.js, you must have the basic knowledge of JavaScript and any programming language.

Overview of Node.js

What is Node.js?

Node.js is a server-side platform built on Google Chrome’s JavaScript Engine (V8 Engine). Node.js was developed by Ryan Dahl in 2009 and its latest version is v0.10.36. The definition of Node.js as supplied by its official documentation is as follows −
Node.js is a platform built on Chrome’s JavaScript runtime for easily building fast and scalable network applications. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices.
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

Following are some of the important features that make Node.js the first choice of software architects.
• 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.
• Very Fast − Being built on Google Chrome’s V8 JavaScript Engine, Node.js library is very fast in code execution.
• 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.
• No Buffering − Node.js applications never buffer any data. These applications simply output the data in chunks.
• License − Node.js is released under the MIT license.

Who Uses Node.js?

Following is the link on github wiki containing an exhaustive list of projects, application and companies which are using Node.js. This list includes eBay, General Electric, GoDaddy, Microsoft, PayPal, Uber, Wikipins, Yahoo!, and Yammer to name a few.
• Projects, Applications, and Companies Using Node

Concepts

The following diagram depicts some important parts of Node.js which we will discuss in detail in the subsequent chapters.

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Where to Use Node.js?

Following are the areas where Node.js is proving itself as a perfect technology partner.
• I/O bound Applications
• Data Streaming Applications
• Data Intensive Real-time Applications (DIRT)
• JSON APIs based Applications
• Single Page Applications

Where Not to Use Node.js?

It is not advisable to use Node.js for CPU intensive applications.

So, this brings us to the end of blog. This Tecklearn ‘Overview of NodeJS’ blog helps you with commonly asked questions if you are looking out for a job in NodeJS Programming. If you wish to learn NodeJS and build a career in NodeJS Programming domain, then check out our interactive, Node.js Training, that comes with 24*7 support to guide you throughout your learning period.

Node.js Training

About the Course

Tecklearn’s Node.js certification training course familiarizes you with the fundamental concepts of Node.js and provides hands-on experience in building applications efficiently using JavaScript. It helps you to learn how to develop scalable web applications using Express Framework and deploy them using Nginx. You will learn how to build applications backed by MongoDB and gain in-depth knowledge of REST APIs, implement testing, build applications using microservices architecture and write a real-time chat application using Socket IO. Accelerate your career as a Node.js developer by enrolling into this Node.js training.

Why Should you take Node.js Training?

• As per Indeed.com data, the average salary of Node.js developer is about $115000 USD per annum.
• IBM, LinkedIn, Microsoft, GoDaddy, Groupon, Netflix, PayPal, SAP have adopted Node.js – ITJungle.com
• There are numerous job opportunities for Node.js developers worldwide. The job market and popularity of Node.js is constantly growing over the past few years.

What you will Learn in this Course?

Introduction to Node.js

• What is Node.js?
• Why Node.js?
• Installing NodeJS
• Node in-built packages (buffer, fs, http, os, path, util, url)
• Node.js Modules
• Import your own Package
• Node Package Manager (NPM)
• Local and Global Packages

File System Module and Express.js

• File System Module
• Operations associated with File System Module
• JSON Data
• Http Server and Client
• Sending and receiving events with Event Emitters
• Express Framework
• Run a Web Server using Express Framework
• Routes
• Deploy application using PM2 and Nginx

Work with shrink-wrap to lock the node module versions

• What is shrink-wrap
• Working with npmvet
• Working with outdated command
• Install NPM Shrinkwrap

Learn asynchronous programming

• Asynchronous basics
• Call-back functions
• Working with Promises
• Advance promises
• Using Request module to make api calls
• Asynchronous Commands

Integration with MongoDB and Email Servers

• Introduction to NoSQL Databases and MongoDB
• Installation of MongoDB on Windows
• Installation of Database GUI Viewer
• Inserting Documents
• Querying, Updating and Deleting Documents
• Connect MongoDB and Node.js Application
• Exploring SendGrid
• Sending emails through Node.js application using SendGrid

REST APIs and GraphQL

• REST API
• REST API in Express
• Postman
• MongoDB Driver API
• Express Router
• Mongoose API
• GraphQL
• GraphQL Playground

Building Node.js Applications using ES6

• ES6 variables
• Functions with ES6
• Import and Export withES6
• Async/Await
• Introduction to Babel
• Rest API with ES6
• Browsing HTTP Requests with Fetch
• Processing Query String
• Creating API using ES6
• Building Dashboard API
• Creating dashboard UI with EJS
• ES6 Aside: Default Function Parameters
• Data Validation and Sanitization

User Authentication and Application Security

• Authentication
• Types of Authentication
• Session Vs Tokens
• JSON Web Tokens
• Bcrypt
• Node-local storage

Understand Buffers, Streams, and Events

• Using buffers for binary data
• Flowing vs. non-flowing streams
• Streaming I/O from files and other sources
• Processing streams asynchronously
• File System and Security

Build chat application using Socket.io

• Getting Started
• Adding Socket.io To Your App
• Exploring the Front-end
• Sending Live Data Back & Forth
• Creating the Front-end UI
• Showing Messages In App
• Working with Time
• Timestamps
• Show Message Time In Chat App
• Chat application Project

Microservices Application

• Why Microservices?
• What is Microservices?
• Why Docker?
• What is Docker?
• Terminologies in Docker
• Child Processes
• Types of child process

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