Amazon EventBridge has 4 Core Concepts which's are

Event Sources

Event Buses

Rules

Targets

The basis of EventBridge is to create rules that route events to a target.

So lets learn our core concepts of Amazon EventBridge Events — Event Buses — Rules — Targets.

Event Sources

An event indicates a change in an environment such as an AWS environment, a SaaS partner service or application, or one of your applications or services. Event Sources publish events to the Event Buses.

Events are represented as JSON objects and they all have a similar structure, and the same top-level fields. The following event in Amazon EventBridge indicates an Amazon EC2 instance being terminated.

https://medium.com/aws-lambda-serverless-developer-guide-with-hands/amazon-eventbridge-decouple-services-with-event-driven-architecture-9643b2f5290f