This is not a distinction that will appear in many places, but I think it is a useful one. Basically, it describes the difference between versions of postmodernism which try to show the "cracks" or "gaps" in the modernist metanarratives, and the versions which investigate the edges or boundaries of local narratives as they interact with other local narratives. The first describes the work of Jacques Derrida, in the 1970s particularly, and the second describes the hermeneutical tradition, including Martin Heidegger, Hans-Georg Gadamer, and Paul Ricoeur.