This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book deals with issues in the ontology of videogames, asking questions about the nature of videogames themselves. It provides a positive ontology of videogames that identifies a particular videogame with its algorithm. The book investigates important connections between videogames and some perennial debates within aesthetics. It develops a new account of the aesthetics of videogames. The book considers various claims that might be, and sometimes have been, made concerning the relationship between videogames and creativity. It also investigates the effect that a new wave of virtual reality technology is having on the representational and interactive media of videogames. The book also considers the relationship between videogames and broader social issues, particularly regarding how people and their actions are represented within videogames. It examines the ethics of the sexualization of women in videogames, and also focuses on the Japanese genre of eroge videogames.