Understanding data structures is fundamental for mastering algorithms. In order to solve problems and tasks, students must be able to choose the most appropriate data structure in which the data is stored and that helps in the process of the solution. Of course, there is no single correct solution, but in many cases, it is an important step to find the most efficient data structure to solve the task. In this paper, I will present the most common data representations and data structures that can help get to know them, to master them, and then to reuse them for solving different tasks.