Data without algorithms are like algorithms without data: one is as useless as the other. Neither can exist without the other. Similarly, objects in the natural environment are always connected to actions, whether they are possible and permitted or possible and partially prohibited. Each object has its own set of action possibilities: what can be done with one object cannot necessarily be done with another, or at least not in the same way. This book aims to demonstrate that such a natural relationship exists between objects and actions, or between data and algorithms. It also seeks to prove that it makes no sense to develop one independently of the other. Every decision on one side has consequences for the other side. The field of computer science education is adapting to this reality: in the past, the focus was on initial training.