Module 2: What's Node.js?

We've talked a lot about what the backend is and what you need to know about JavaScript to use NodeJS efficiently. Now, let's delve into the ultimate question: what exactly is NodeJS?

To answer this, let's refer to the official documentation:

NodeJS is an open-source and cross-platform JavaScript runtime environment. It is a popular tool for almost any kind of project! NodeJS runs the V8 JavaScript engine, the core of Google Chrome, outside of the browser. This allows NodeJS to be very performant.

But what does this mean? Let's break it down step by step to understand the significance of NodeJS in modern web development.

1. Open Source:

NodeJS is open source, which means its source code is publicly available for anyone to view, modify, and distribute. This openness fosters a vibrant community of developers who contribute to its growth and improvement.

Take a look at the NodeJS GitHub repository yourself! Everything related to NodeJS lives there. You can access the source code, see how it works under the hood, and even contribute to its development if you wish.

2. Cross-Platform:

Being cross-platform means NodeJS can run on multiple operating systems, including Windows, macOS, and Linux. This flexibility makes it a versatile tool for developers, as they can write code once and run it anywhere. Whether you're developing on a MacBook, deploying on a Linux server, or testing on a Windows machine, NodeJS has you covered.

3. JavaScript Runtime Environment:

To understand what a JavaScript runtime is, we need to look at how JavaScript traditionally runs. JavaScript is primarily known as a scripting language for web browsers. Browsers have built-in engines (like Google Chrome's V8 engine) that read and execute JavaScript code, translating it into machine code that computers can understand.

However, JavaScript isn't just limited to browsers. What if you want to run JavaScript on a server or outside of a web browser? This is where NodeJS comes in. NodeJS provides a runtime environment outside of the browser, essentially using the V8 engine outside of the browser. This decision enabled JavaScript to be used in places where it traditionally wasn't, such as servers and embedded systems.

4. The V8 Engine:

NodeJS utilizes the V8 engine, developed by Google for the Chrome browser, to execute JavaScript code. The V8 engine compiles JavaScript directly to machine code, making it extremely fast and efficient. By leveraging V8, NodeJS allows developers to use JavaScript for server-side scripting, creating scalable, high-performance applications.