There are many courses and materials available about the object oriented programming (OOP). Although many of them are very solid and accurate, in my opinion most of them fail to catch the meritum of this programming paradigm. As opposed to other materials, which focus mainly on object relationships, like ‘has-a’ or ‘is-a’, or go into great lengths about code encapsulation, I would like to offer a learning perspective focusing on polymorphism. Once we establish a solid understanding of polymorphism, we’ll see how this paradigm can also be applied to code-free designs and what benefits it can have. This article is a little bit more code-heavy, but hopefully my descriptions and explanations will help you go through it even if code is not your thing. The common knowledge When we look at courses explaining what OOP is, they usually put the most emphasis on the structural framework that the paradigm is built upon. We learn about classes that can be instantiated to create objects. We’r