The business rules is a very strange concept to deal with on our first encounter as traditional developers, and the purpose of this first chapter was to present how they fit in our everyday application development and why they can help us define better systems.

We've seen what rules are, defined their structure, and covered their practical uses. We've also covered a few examples of projects where rules are useful—and some other examples where they might be not necessary. We've also introduced our eShop project, which will guide us through the next few chapters in order to establish all the benefits Drools 6 provides, from Business Rule writing to Rule Engine configuration.

In the next chapter, we will start writing our first business rules and take our first steps in defining our rule-based projects.