This book provides an introduction to the complex world of digital platforms. Its essence is conveyed in an understandable manner and illustrated with practical examples. In doing so, the author sheds light on a defining core element of digitalization. A better understanding of the nature and power of digital platforms is urgently needed, as they increasingly play a strategic role in all areas of the economy and life. The author explains the core components and internal mechanisms of digital platforms. Additionally, it offers suggestions and principles for designing digital platform ecosystems.