In Node.js, the core API is built around an asynchronous event-driven architecture in which certain objects called "emitters" send named signals called "events" to other objects called "listeners" that perform specific actions in response.

The EventEmitter class

All objects that emit events are instances of the EventEmitter class defined in the node:events module:

const EventEmitter = require('node:events');

When the EventEmitter object emits an event, all the functions attached to that specific event are called synchronously.

Creating an event emitter

To create an event emitter object, you can use the new keyword to instantiate the EventEmitter class:

const EventEmitter = require('node:events');const emitter = new EventEmitter();

Emitting named events

To emit a named event, you can use the emit() method of the event emitter instance:

emitter.emit(name, ...arguments?);

Where: