How does Node.js handle asynchronous code internally? Explain the event loop

phases.

Node.js uses the event loop to handle async tasks without blocking.

Main phases:

• Timers: Executes callbacks scheduled by setTimeout and setInterval.
• Pending callbacks: Executes I/O callbacks deferred to next iteration.
• Idle, prepare: Internal operations.
• Poll: Retrieves new I/O events; executes I/O callbacks.
• Check: Executes callbacks scheduled by setImmediate.
• Close callbacks: Handles closed connections.

Tasks are processed in this order each loop iteration.