This book is a living exposition of the great approach of the authors to quantum processes. Unparalleled features of the quantum world in this book are explained in the language of diagrams - an innovative visual method of presenting complex theories. Applied formalism allows you to develop an intuitive understanding of quantum features without complex calculations - basic mathematical training is enough to read This purely diagrammatic presentation of quantum theory is the fruit of 10 years of research combining classical methods of linear algebra and Hilbert spaces with advanced achievements in the field of quantum computing and the foundations of quantum theory. The book is written in simple language, with humor and includes more than 100 exercises. The publication will be useful as an initial course on the foundations of quantum theory and quantum computing for students, as well as for scientists from different fields of physics, biology, linguistics and cognitive science.