What is Node.js?

What is Node.js?

Node.js is an open-source, cross-platform JavaScript runtime built on Chrome's V8 engine. It allows developers to execute JavaScript code outside the browser, making it possible to build scalable network applications using a single programming language across the entire development stack.

It allows the developers to run JavaScript code outside the browser, enabling server-side scripting.

Key Features:

• Event-Driven Architecture: Uses an event loop to handle asynchronous operations (e.g., file I/O, network requests).
  • At the core of Node.js is the event loop – a mechanism that process asynchronous callbacks. When an I/O operation (like file reading or database querying) is initiated, Node.js delegates the task and continues executing subsequent code. Once the task completes, a callback function is triggered, ensuring the system remains non-blocking and responsive.
• Non-Blocking I/O: Processes multiple operations concurrently without waiting for one task to finish.
• Single-Threaded: Utilizes a single-threaded event loop model but scales via worker threads for CPU-heavy tasks.

History and Evolution:

• Created by Ryan Dahl in 2009 to address the limitations of traditional server-side languages.
• It's innovative non-blocking I/O model transformed web server development by replacing the conventional multi-threaded approach with a more efficient event-driver paradigm.

Node.js vs Traditional Server-Side Languages

When to Use Node.js

• Real-time apps (e.g., chat, live updates).
• APIs requiring high throughput.
• Microservices and serverless architectures.

When Not to Use Node.js:

• CPU-intensive tasks (e.g., vide encoding).
• Applications requiring heavy computational threading.

Key Takeaways

• Node.js is not a framework but a runtime for executing JavaScript on the server.
• Its non-blocking I/O model makes it ideal for scalable, real-time applications.