In this chapter we propose a framework for comparing media systems. We propose, specifically, four major dimensions according to which media systems in Western Europe and North America can usefully be compared: (1) the development of media markets, with particular emphasis on the strong or weak development of a mass circulation press; (2) political parallelism; that is, the degree and nature of the links between the media and political parties or, more broadly, the extent to which the media system reflects the major political divisions in society; (3) the development of journalistic professionalism; and (4) the degree and nature of state intervention in the media system. Note that each of these can be seen in some sense as a single, quantitative dimension. That is, we can speak about high or low levels of press circulation, political parallelism, journalistic professionalism, or state intervention. But we shall also see that each of these dimensions is complex and that many more subtle qualitative distinctions become important as we begin to analyze concrete media systems. In many cases we will also introduce related, minor dimensions along which media systems may vary. Ours is not, of course, the first attempt to set forth a framework of this sort. We have tried to build on previous work, refining it based on our attempt to make sense of the patterns of difference and similarity we have found among the countries covered here, and to link these patterns to the social and political context in which they evolved.