Async Code in Node.js: Callbacks and Promises

Asynchronous programming in Node.js prevents blocking the single main thread, allowing efficient, non-blocking I/O operations through callbacks and promises. While callback-based approaches can lead to complex "callback hell," Promise-based handling offers better readability and streamlined error management. Why async code exists in Node.js Node.js is built on a non-blocking, single-threaded architecture. That means it can handle multiple operations at once—but only if those operations don’t blo