This book explores the multiple facets of habit from diverse and complementary theoretical frameworks. It provides a complete overview of the cognitive, computational, and neural processes underlying the formation of distinct forms of habit. The objective of the book is to cover (1) the multiple definitions of the habit construct and the relation between different habit-related concepts, (2) the underlying brain circuits of habits, and (3) the possible involvement of habits in psychiatric disorders such as alcohol and substance use disorder. This book will be of interest to all researchers in behavioral and computational neuroscience, psychology, and psychiatry who are interested in associative learning and decision making, under normal and pathological conditions.