While innovation has always been the lifeblood of any economic system, the forms this notion takes today may seem confusing. These new design regimes require to collectively support creative reasoning which strongly destabilize the traditional representations we have of known objects and organizations. C-K theory was born in Management Science Lab of Mines ParisTech in a modeling effort the activities undertaken in innovative design processes. The prospect of a better understanding of the characteristics of design led to the development of formal and practical aspects of C-K theory. If the theory is now established in the academic world and applied in a variety of industrial contexts, it had not yet been presented to a wider audience. This book presents briefly some elements of theory illustrated by examples as well as tools and methods that have been developed jointly by researchers and their industrial partners.