This chapter comes to show the three perspectives on machine learning, i.e., the subtitle of this book. We start from the discussion between learning and perspectives. Next, we review the foundations of machine learning such as mathematics, logic, information theory, decision theory, and neuroscience. Discussed on the difficulties in studying machine learning, we propose the viewpoints on machine learning. We then focus on the three perspectives: learning frameworks, learning paradigms, and learning tasks, which corresponds to six learning frameworks, three main machine learning paradigms, and seven representative machine learning tasks, respectively. Finally, we give the logical and hierarchical illustrations between the three perspectives.