Buddhas of The Ten Directions What are the Buddhas of the ten directions?  What are the applications of this teaching in the Buddhist traditions?
Firstly, what are the 10 directions:


  "Specifically, the ten directions are the eight directions of the
  compass—north, south, east, west, northwest, northeast, southeast, and
  southwest—plus up and down."


ref: http://www.sgilibrary.org/search_dict.php?id=2245

Second, sutras that attempt to list and describe the 10 buddhas.
http://www.tientai.net/teachings/dharma/buddha/10directions.htm

The traditional cosmology imagined that there could only be one Buddha in the world at a time. By imagining more universes, there could be more than one Buddha.

I think the particular phrase is one of the rhetorical flourishes you see a lot of in Mahayana-- it's a nice way to say all the Buddha's, everywhere.  The various names of the realms and 10 Buddhas mentioned in the Dasabhumika (realms like "Without Distress" or "Skillfulness") and Buddha's name "Virtue of Goodness" and "Practicing the 3 vehicles" are reminders of what the goals of Buddhism are and what is worth emulating.