Event Emitter

The Node.js API is based on an event-driven architecture. It includes the events module, which provides the capability to create and handle custom events. The event module contains EventEmitter class. The EventEmitter object emits named events. Such events call the listener functions. The Event Emitters have a very crucial role the Node.js ecosystem. Many objects in a Node emit events, for example, a net.Server object emits an event each time a peer connects to it, or a connection is closed. The fs.readStream object emits an event when the file is opened, closed, a read/write operation is performed. All objects which emit events are the instances of events.EventEmitter.