There are seven fundamental building blocks of event processing. Some building blocks contain references to others.

1. The event producer represents an application entity that emits events into the event processing networks (EPN)
2. The event consumer is an application entity that receives events, Simply it consumes an event
3. The event processing agent building block represents a piece of intermediary event processing logic inserted between event producers and event consumers
4. Event types will represent different type of events, event-driven application will involve one or more different types of events
5. An event channel is to route events between event producers and event consumers
6. A context element collects a set of conditions from various dimensions categorize event instances so that they can be routed to appropriate agent instances
7. A global state element refers to data that is available for use both by event processing agents and by contexts

Event Processing Agents

There are several different kinds of event processing agents (EPA).Below diagram shows the inheritance hierarchy of the various EPA.

Agent technology handles extreme scalability issues. Agents are characterized by being autonomous, having interactions, and being adaptive. CEP engines can be autonomous and interactive to the extent that they simply respond to multiple (complex and continuous) events; adoptability could be via machine-learning or more commonly via statistical functions.