Debates about digitalization and democracy have always been controversial and range from optimistic views to sceptic or even dystopian perspectives. The former emphasize the potential of the internet to drive innovation in society and to enhance democracy. In contrast, skeptical views highlight the risks and even threats of digitalization. This finds expression in aspects such as the growing relevance of fake news online. Algorithmic filtering promotes visibility of polarizing content. Furthermore, social media can no longer be seen as neutral gathering places for public discourse. All of this makes it necessary to further research the role of digitization with regard to strengthening and preserving democracy. This open access book brings together the results of a five-year interdisciplinary research project on digital transformation in society.