Tutorial: “Change Detection fundamentals and applications to learning in nonstationary environments ” This tutorial presents an overview of machine learning methods designed to operate on streaming data, forcing the learner to operate incrementally. As a critical step in many "Learning in Nonstationary Environments" contexts, the change-detection problem will be formulated, and the mainstream solutions presented. Special emphasis will be given to illustrating how change-detection algorithms enable learning in nonstationary environments, as well as the active and passive learning approaches. The tutorial is accompanied by various examples where learning in nonstationary environments and change-detection algorithms are applied to solve real-world problems, such as fraud detection in a datastream of credit card transactions. This tutorial will be an updated version of the tutorial https://boracchi.faculty.polimi.it/Tutorials/AnomalyAndChangeDetectionTutorial_ICPR2020.html Short Bio Giacomo Boracchi is Associate Professor of Computer Engineering at Dipartimento di Elettronica, Informazione e Bioingegneria of the Politecnico di Milano (DEIB). Giacomo has received a Ph.D. in information technology (DEIB, 2008), and an MSc degree in Mathematics (Universitá Statale di Milano, 2004). His primary research interests concern image processing and machine learning, in particular, image restoration and analysis, change/anomaly detection, domain adaptation, and learning in nonstationary environments. He has been/currently is the advisor of 8 Ph.D. students, regularly teaching deep learning and image processing courses and giving tutorials at major conferences (ICASSP, ICIP, ICPR, IJCNN). He is currently leading research projects applying machine learning and image-understanding algorithms to design new industrial solutions with STMicroelectronics, Gilardoni Raggi X, and Cisco. He is the author of more than 90 papers in international conferences and journals, and since 2018 he has served as an Associate Editor for the IEEE Transactions on Image Processing. In 2015 he received the IBM Faculty Award; in 2016 the IEEE Transactions on Neural Networks and Learning Systems Outstanding Paper Award; in 2017, the Nokia Visiting Professor Scholarship; in 2021, an nVidia Applied Research Grant. CV: https://boracchi.faculty.polimi.it/docs/Giacomo_Boracchi_CV.pdf