The huge quantity of data generated daily contain, more or less explicitly, an also huge and valuable amount of knowledge. Such knowledge ends up being the key to success in many environments of everyday life: it enables a business to know which products it has to promote according to the reactions of its customers in social networks; in the medical field it can assist diagnoses through images or in predicting the evolution of a pandemic; in designing optimal transport routes it can be a determining factor for predicting traffic conditions during shipments etc. The data-transformation process in knowledge is subject studied by data science.