I sometimes see it in examples and referenced in the documentation, but I can't really wrap my head around it.
http://matplotlib.org/users/artists.html
http://matplotlib.org/users/transforms_tutorial.html
http://matplotlib.org/users/path_tutorial.html
http://matplotlib.org/users/event_handling.html
http://matplotlib.org/users/artists.html
http://matplotlib.org/users/transforms_tutorial.html
http://matplotlib.org/users/path_tutorial.html
http://matplotlib.org/users/event_handling.html