In the last decades, the rising Big Data revolution together with the consolidation of High Computing capacity led to the evolution of computer systems, able now to perceive their environment thanks to the extraction of meaningful information, developing learning capacities to be self-adaptable. The depicted context has laid the perfect foundations of "Machine Learning", a subfield of Artificial Intelligence, considered at the forefront for the construction of a smart society. Its spreading is being affected all domains, finding application in medicine, transport, environment, and all industrial sectors, with the objective not only of automatizing static activities performed by human beings but also supporting them in taking decisions for more complex and dynamic challenges, capturing valuable knowledge in some cases not directly human-accessible.