Node.js is an open-source, cross-platform JavaScript runtime environment that executes JavaScript code outside of a web browser. It allows developers to run JavaScript on the server-side, creating server-side applications with JavaScript.

One of the key features of Node.js is its event-driven, non-blocking I/O model, which makes it a popular choice for building high-performance, scalable network applications.

Getting Started with Node.js

To get started with Node.js, you'll first need to install it on your computer. You can download the installer from the official Node.js website (nodejs.org) and run it to install Node.js.

Once you have Node.js installed, you can use the Node.js command-line interface (CLI) to run JavaScript code on your computer. To test that Node.js is installed correctly, open a command-line interface and run the following command:

node -v

This command should display the version of Node.js that is currently installed on your computer.

Creating a Node.js Application

To create a Node.js application, you'll first need to create a new directory for your project. Inside this directory, create a new file named index.js. This file will be the entry point for your application.

You can then add the following code to your index.js file:

console.log('Hello, Node.js!');

This code simply logs the string "Hello, Node.js!" to the console.

To run your Node.js application, open a command-line interface and navigate to the directory where your index.js file is located. Then, run the following command:

node index.js

This command will execute your Node.js code and you should see the string "Hello, Node.js!" logged to the console.

Node Package Manager (npm)

Node.js comes with a package manager called npm, which stands for Node Package Manager. npm allows you to easily install and manage third-party libraries and modules for use in your Node.js applications.

You can use npm to install a library by running the following command:

npm install [library-name]

For example, to install the popular "Express" library, which is often used for building web servers, you would run the following command:

npm install express

In conclusion, Node.js is a powerful and versatile runtime environment that allows you to run JavaScript on the server-side. Its non-blocking I/O model makes it well suited for building high-performance, scalable network applications. With its package manager, npm, it makes it easy to use and manage third-party libraries and modules.