Node.js Introduction

What is Node.js?

Node.js is a server-side runtime that executes JavaScript outside the browser.

It uses a non-blocking, event-driven architecture for high performance.

Built on Chrome's V8 engine, it ensures fast code execution.

Ideal for APIs, microservices, and real-time applications.

How does Node.js Work?

• Single-Threaded Event Loop : Uses a single thread with an event-driven model to handle multiple requests efficiently.
• Non-Blocking I/O : Performs asynchronous operations without waiting, improving performance.
• V8 Engine : Executes JavaScript at high speed by converting it into machine code.
• Event-Driven Architecture : Uses events and callbacks to manage tasks efficiently.
• Libuv Library : Handles asynchronous tasks like file system operations, networking, and timers.
• Modules & npm : Provides built-in modules and access to thousands of open-source packages.
• Streaming & Buffering : Processes large data efficiently without loading everything into memory.
• Cross-Platform Support : Runs on Windows, macOS, and Linux.
• Scalability : Ideal for handling concurrent connections in real-time applications.

Why Node.js?

Node.js and Asynchronous Programming

A web server often needs to read a file and send its content to the client.

How traditional servers (PHP, ASP) handle a file request:

• Sends the request to the file system.
• Waits until the file is opened and read.
• Returns the content to the client.
• Moves to the next request.

How Node.js handles a file request:

• Sends the request to the file system.
• Immediately moves on to handle other requests.
• Once the file is read, it sends the content to the client.

What Can Node.js Do?

Node.js can render dynamic web pages.

Node.js can manage files by creating, reading, updating, and deleting them on the server.

Node.js can process and handle user input from forms.

Node.js can interact with databases to insert, update, and remove records.

What is a Node.js File?

A Node.js file defines operations triggered by specific events.

Common events include incoming server requests on a specified port.

Node.js files need to be executed on the server to function.

These files use the ".js" extension, like standard JavaScript files.