A polymorphous concept, power has imposed itself since ancient times. Whether it characterizes the phenomena of domination, exclusion or voluntary submission, it illuminates social relations and, since the 20th Century, interpersonal relations. This book offers, first of all, a daring panorama through its intertwining of different theoretical propositions relating to power, across time and across disciplines. It then presents the work of researchers in information and communication sciences who draw from these proposals the materials allowing them to develop their own analyses. These analyses revisit discursive power with respect to contemporary formations of communication and information. They investigate digital technologies by problematizing the phenomena of influence, control and access to knowledge. Finally, they reflect on the media in the light of inherent powers of social mediation, advertising and journalism.