This element shows, based on a review of the literature, how digital technology has affected liberal democracies with a focus on three key aspects of democratic politics: political communication, political participation, and policy-making. The impact of digital technology permeates the entire political process, affecting the flow of information among citizen and political actors, the connection between the mass public and political elites, and the development of policy responses to societal problems. This element discusses how digital technology has shaped these different domains, identifies areas of research consensus as well as unresolved questions, and argues that a key perspective involves issue definition, that is, how the nature of the problems raised by digital technology is subject to political contestation.