This book is not an introduction to ML. There are many books, courses, and resources available for ML theories, and therefore, this book shies away from these concepts to focus on the practical aspects of ML. You don't have to know these topics inside out--for concepts whose exact definitions can take some effort to remember, e.g., F1 score, we include short notes as references--but you should have a rough sense of what they mean going in. While this book mentions current tools to illustrate certain concepts and solutions, it's not a tutorial book. Tools go in and out of style quickly, but fundamental approaches to problem solving should last a bit longer.