In this book, all fundamental data structures are presented: stacks, queues, indexes, classes, arrays, graphs. For each type of structure, a fundamental but also many alternative implementation methods are given, through various data structures (tables, chains, balanced trees, B-trees, threaded trees, etc.) In the first part, all the foundations are given so that it constitutes a complete and autonomous introductory course. In the second, additional functions and a wide variety of alternative implementations are provided. In the third, special topics are taught (self-adjustment, persistence, etc.), necessary for advanced Computer Science studies. The content of the book covers classical, but also many completely modern topics of the last decade.