An event is the occurrence of something deemed significant in a software application, such as a state change, that may be of interest to other applications or other components within the same application. An example of an event is the placement of a purchase order or the posting of a letter grade for a course that a student is taking.
An event-driven architecture (EDA) is a distributed, asynchronous software architecture pattern that integrates applications and components through the production and handling of events. By tracking events, we don't miss anything of significance related to the business domain.
EDAs are loosely coupled. The producer of an event does not have any knowledge regarding the event subscribers or what actions may take place as a result of the event.
SOA can complement EDA because service operations can be called based on events...
