This chapter is the introductory chapter of this book. It provides an overview of the content and structure that readers can expect from this book. After an initial overview of the book’s organization, the chapter presents the scope of this scope by providing contextual information, such as definitions for the terms “screen-reader users” and “visualization creators.” Additionally, the chapter establishes the distinction between “accessibility of data visualizations” and “visualizations of accessibility,” clarifying that the focus of this book is on the former. Furthermore, the chapter discusses the motivation behind this work.