Event channels

Before we cover the two main event topologies for EDAs, let's go over the concept of event channels because both topologies make use of them.

Event messages contain data about an event and are created by event producers. These event messages use event channels, which are streams of event messages, to travel to an event processor.

Event channels are typically implemented as message queues, which use the point-to-point channel pattern, or message topics, which use the publish-subscribe pattern.