In the Salesforce Aura Components framework, which follows a publish-subscribe pattern for events, an application event is fired using the fire() method. A component first gets an instance of the event using $A.get("e.namespace:eventName"). After optionally setting parameters on the event instance using setParams(), the component calls the fire() method on that instance. This action broadcasts the event to all components that have a registered handler for it.

1. Salesforce Aura Components Developer Guide

"Firing Application Events": The official documentation explicitly demonstrates firing an application event. The example code shows getting the event and then calling the fire() method on the event object.

Reference: In the section on Application Events

the guide states: "To fire an application event

you get an instance of the event in JavaScript and call fire() on it." The accompanying code example is: appEvent.fire();.

2. Salesforce Aura Components Developer Guide

"Component Events": The same fire() method is used for component events

reinforcing its role as the standard event-firing mechanism in the framework.

Reference: The "Firing Component Events" section provides a similar pattern: "Get an instance of the event by name... Fire the event by calling fire() on your event instance."