From the beginning we have said that Scala is a completely object-oriented language. You have been using objects and calling methods on them since back in chapter 2 when we were taking our first steps in the language. Despite this, we have actually done very little with object-orientation. This has been intentional. So far we have been building up your logic skills and teaching you to break problems up into different functional units. Now that your problem solving skills have reached a sufficient level we will take the next step to doing full object-oriented decomposition of problems. We finish this book by giving you a brief introduction to object-orientation and how to do it in Scala.