The aim of this chapter is to suggest ways to better capture the diversity of constellations and the dynamics of interactions in the public sphere, triggered by the digital transformation. The starting point is the question of why relations and dynamics should be considered more in communica tion studies and how they have been researched so far. In this respect, the limits of public sphere theory and social network analysis (SNA) are discussed. To overcome these limits, I propose a theoretical framework that combines public sphere theory and SNA with – as a third and new concept – modes of interaction. Such modes of interaction are ideal-typical patterns of interaction between actors in different constellations – namely, diffusion, mobilization, conflict, cooperation, competition, and scandal. Afterwards, I discuss these modes of interaction in the context of different societal subsystems and phases of media change in order to demonstrate their heuristic value. Traditional mass media foster the universalization of competition in several dimensions because competition requires only one- way relations of observation and influence. The Internet supports the interactive, multi-stage, and sequential communication that is characteristic of conflict and cooperation.