This guide explores Node.js (Node) and its relationship with npm, the Node Package Manager. Let's start with the basics:

• Node.js is server-side JavaScript: Unlike browser-based JavaScript, Node utilizes V8, Chromium's JavaScript engine, to execute JavaScript outside the browser environment. While both share the same core language, their capabilities and applications differ significantly.
• npm is independent of Node: You don't need Node.js knowledge to use npm.

npm, despite its playful alternative names on its website, fundamentally combines "Node" and "Package Manager." We'll delve into package managers later; this chapter focuses on Node.js.

Guide Chapters:

1. Audience of This Guide
2. Understanding "npm"
3. Command Line Basics
4. Exploring Node.js (Current Chapter)
5. Package Managers Explained
6. Installing npm
7. Installing npm Packages
8. npm Commands
9. Installing Existing npm Projects

Node.js: JavaScript Beyond the Browser

JavaScript's traditional role is within web browsers alongside HTML and CSS. However, Node.js extends JavaScript's reach to server-side programming.

This was a significant breakthrough. JavaScript no longer requires a browser to function. Hence, the distinction between "Node JavaScript" and "browser-based JavaScript."

Server-Side vs. Client-Side

Client-side languages (HTML, CSS, JavaScript) operate within the user's browser, while server-side languages (PHP, Ruby, Python, etc.) execute on a server. Server-side languages typically offer broader functionalities.

The creation of Node.js, spearheaded by Ryan Dahl, leveraged JavaScript's speed (especially compared to PHP and Ruby) to enable its use across various environments.

How Node.js Works

Node.js essentially runs JavaScript as a server-side language outside the browser. This is achieved through the use of JavaScript engines like V8 (Chromium's engine), which can operate independently. V8's popularity stems from Chrome's widespread use.

The ability to extract the JavaScript engine from the browser and run it independently makes server-side JavaScript a reality.

Node.js: Similar Yet Different

While Node.js and browser-based JavaScript share the same core language and syntax, they differ significantly in their capabilities. Browser-specific APIs (like window, document, and fetch) are absent in Node.js. However, console.log remains a valuable tool, and Node.js offers its own unique APIs, such as the process object.

Over time, Node.js and browser-based JavaScript have evolved along separate paths, resulting in distinct features and development approaches. The analogy of an upright bass and an electric bass guitar aptly illustrates their similarities and differences.

Node.js provides server-side functionalities like file system access, system-level API interaction, email handling, request handling, and task scheduling.

Local Node.js Execution

Node.js typically comes bundled with npm. While Node.js installation is necessary for its use, npm can be utilized without in-depth Node.js knowledge. We'll cover installation in a later chapter.

To test Node.js (if installed), create a test.js file with simple JavaScript code:

console.log('Node.js is running!');

const numbers = [1, 2, 3, 4, 5];

numbers.forEach(number => {
  console.log(number);
});

Run this using node test.js in your terminal. You can also use node to enter an interactive Node.js environment.

Next Steps

This chapter provided a foundational understanding of Node.js. Node.js's ability to run JavaScript outside the browser enables the creation of server-side packages, managed by npm. The next chapter explores package managers in detail.

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