In CEP, a combination of simple and ordinary events is taken into consideration in order to judge it a complex event has happened. The various events that are taken into consideration may be evaluated over a long period of time. The event correlation between the various events may occur in various dimensions, such as temporal, causal, and spatial. For this evaluation to happen, CEP requires the following components:

• Event interpreters
• Event pattern definition
• Event pattern matching
• Event correlation techniques

CEP is generally used to respond to anomalies in business, and in order to assess the opportunities and threats.

EDA patterns come in two different flavors or topologies. Each topology needs to be implemented only in specific scenarios as their features and characteristics are different. Hence, it is very important to understand these topologies so wise decisions can be made regarding their choice and implementation. In the next section, we will understand the various EDA pattern topologies.