Node.js applications rely on an event-driven architecture to efficiently handle asynchronous operations. At the heart of this architecture is the built-in events module, which provides the foundation for working with events and event emitters. This module enables you to create objects that can emit named events and register listeners for those events, allowing different parts of your application to communicate without being tightly coupled.

The primary class provided by the events module is EventEmitter. This class allows you to define custom events, attach listeners to those events, and emit events when certain actions occur. Many core Node.js modules, such as streams and HTTP servers, are built on top of EventEmitter, making it an essential part of Node.js development.