This chapter examines the dimensions of the political communication system. It first explains the rationale for a comparative study of political communication before discussing relevant models of relationship between media and political institutions, as well as differences in political communication cultures among media and political elites. It then reviews findings on country-specific reporting styles in political news coverage and evaluates divergent approaches in government communication and election communication. On the side of the citizens, the chapter explores cross-national differences in the consumption of political news, along with the positive contribution of public service broadcasters for informed and enlightened citizenship. Finally, it looks at political information flows, comparing message production by political actors, political message production by media actors, usage patterns of political information, and effects of political communication.