Can you explain how the Event Loop works in Node.js and its role in asynchronous task processing?

The Event Loop in Node.js is a mechanism that allows asynchronous code to run without blocking the main thread. Node.js operates on a single thread, but thanks to the Event Loop, it can handle multiple I/O operations concurrently.

How it works:

• When an asynchronous operation is initiated (for example, reading a file or making a database request), it is sent to the appropriate system API or queue.
• The Event Loop monitors these operations and, when they complete, places their callbacks into the task queue.
• The main thread processes these callbacks sequentially, invoking them one by one.

Thus, the Event Loop provides non-blocking task processing, enabling Node.js to efficiently handle many simultaneous operations.

Example:

console.log('Start');
setTimeout(() => {
  console.log('Timeout callback');
}, 0);
console.log('End');
// Output will be:
// Start
// End
// Timeout callback