In everyday life, companies are unavoidable. They serve as employers, service providers, investment opportunities, or subjects of criticism. This book explores how companies operate and why they function the way they do. So what distinguishes companies from other types of organizations, such as administrations, schools, or non-governmental organizations? The key to answering these questions lies in examining the two central characteristics of a company: self-financing and decision-making autonomy. Additionally, by distinguishing between formal structure, informality, and façade, a nuanced understanding of the complex inner workings of a company is developed, providing the reader with a toolkit for organizational science for their own analyses and reflections.