What is event?
Event is a immutable statement of fact or anything change in the system.
What is the feature of event-driven architecture
consist of publisher and consumer
1.publisher publish event.
2.consumer consume event.
asynchronous
Publisher and consumer is a asynchronous interaction.
To the other words,when publisher publish a event,consumer not response the action in real-time.
loose coupling
Publisher only publish event,but it not know the next step of the event.
Equally,the consumer is not know about publisher,it only care about the event it need to consume.
