Event hubs are created to help us with the challenge of handling a huge amount of event-based messaging. The idea is that if we have apps or devices that publish a large amount of events in a very short duration (for example, a real-time voting system), then event hubs can be the place where we can send the event.
Event hubs will create a stream of all the events which can be processed at some point in different ways. An event hub trigger is used to respond to an event sent to an event hub event stream.
The following diagram shows how a trigger works with an Event Hub: