What is Node.js? Explain in detail.

Node.js is a JavaScript runtime environment that allows you to run JavaScript code outside of the browser, typically on the server-side.

🔧 Key Features of Node.js:

1. Built on Chrome's V8 engine
   • Fast execution of JavaScript code.
2. Non-blocking I/O and Event-driven architecture
   • Handles multiple requests simultaneously without waiting for any one task to finish (asynchronous).
3. Single-threaded but highly scalable
   • Uses the event loop and callbacks to manage concurrency.
4. npm (Node Package Manager)
   • Largest ecosystem of open-source libraries/packages.

📌 What Can You Do with Node.js?

• Build web servers and APIs
• Create real-time applications (e.g., chat apps)
• Work with databases (MongoDB, MySQL, etc.)
• Develop command-line tools
• Build microservices and backend systems

💡 Example

const http = require('http');

const server = http.createServer((req, res) => {
  res.end("Hello from Node.js!");
});

server.listen(3000, () => {
  console.log("Server is running on port 3000");
});

✅ Why Use Node.js?

• Fast, lightweight, and efficient
• Great for building scalable and real-time applications
• Same language (JavaScript) on both client and server

Summary:

Node.js lets you use JavaScript for backend development, making it ideal for building fast, scalable, and modern web applications.