Drools Frequently Used Terms - rules engine - drools tutorial - business rules engine
What is Frequently Used Terms in Drools?
Rules
- The heart of the Rules Engine where you specify conditions (if ‘a’ then ‘b’).
![learn drools tutorial - how a rule based engine works - drools example programs](https://wikitechy.com/tutorials/drools/img/drools-images/how-rule-based-engine-works.png)
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Facts
- Facts are the data on which the rules will act upon. From Java view, Facts are the POJO (Plain Old Java Object).
![learn drools tutorial - when to use rule engine - drools example programs](https://wikitechy.com/tutorials/drools/img/drools-images/when-to-use-rule-enginer.png)
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Session
- A Data Session in Drools is the core component to fire the rules. It is the knowledge session that holds all the rules and other properties. A Knowledge Session is created from the Knowledge Base. For the rules engine to work, Facts are inserted into the session and when a condition is met, the subsequent rule gets fired. A Session is of two types:
- Stateless Knowledge Session
- Stateful Knowledge Session
![learn drools tutorial - how a rule based engine works - drools example programs](https://wikitechy.com/tutorials/drools/img/drools-images/how-a-rule-based-engine-works.png)
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Agenda
- It’s a rational concept. The program is the logical place where activations are waiting to be fired.
Activations
- Activations are the then part of the rule. Activations are placed in the agenda where the dsssuitable rule is fired.
![learn drools tutorial - imperative vs declarative rule statements - drools example programs](https://wikitechy.com/tutorials/drools/img/drools-images/imperative-vs-declarative-rule-statements.png)
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Drools Fusion
![learn drools tutorial - drools fusion - drools example programs](https://wikitechy.com/tutorials/drools/img/drools-images/drools-fusion.png)
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![learn drools tutorial - drools fusion - drools example programs](https://wikitechy.com/tutorials/drools/img/drools-images/drools-fusion1.png)
![learn drools tutorial - drools fusion workflow management - drools example programs](https://wikitechy.com/tutorials/drools/img/drools-images/drools-fusion-workflow-management.png)
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Drools Flow
![learn drools tutorial - drools flow - drools example programs](https://wikitechy.com/tutorials/drools/img/drools-images/drools-flow.png)
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Drools Guvnor
![learn drools tutorial - drools guvnor - drools example programs](https://wikitechy.com/tutorials/drools/img/drools-images/drools-guvnor.png)
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Drools Planner
![learn drools tutorial - drools planner - drools example programs](https://wikitechy.com/tutorials/drools/img/drools-images/drools-planner.png)
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![learn drools tutorial - drools planner workflow - drools example programs](https://wikitechy.com/tutorials/drools/img/drools-images/drools-planner-workflow.png)
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