Namespace returns the portion of an event key that occurs before the first period.

EventMessage is the message/envelope that brokers use to deliver events to subscribers.

Broker encapsulates a connection/client that can both publish events and subscribe to them.

Publisher is an event source client that can write events to the source/stream.

Subscriber is a broker client/connection that lets you subscribe to asynchronous events that occur elsewhere in the system.

Subscription is simply a registration pointer that can allow you to stop listening at any time.

EventHandlerFunc is the signature for a function that can asynchronously handle an incoming event that was published through a broker and subscribed to by a listener.