In this chapter, we review the physical processes that create the mean and variable circulation features along the eastern margins of the ocean basins. Rather than describing the individual systems, we describe the processes and their variability between the systems, dividing the discussion into the low-, mid- and high-latitude regions. We start with the low latitudes, since their signals often move poleward along the coastal wave guides into the midlatitudes, which are the well-known eastern boundary upwelling systems. Our treatment of the higher latitudes is limited to examples from the better-studied NE Pacific Basin (The Alaska Current).