Introduction
This chapter aims at introducing this book volume and providing the necessary guidelines for reading the contributions described in the various chapters. Therefore, we define here the principles that form the common thread between the book chapters, at the end of which the reader will have an exhaustive overview of the recent frontier issues in the research and development of learning methodologies for nonlinear modeling. For this reason, this chapter first describes what are the key concepts that will be covered in the book and deepened in each chapter.