aplay -D hw:0,0 horse.wav does not work

[philp]

Hi
I'm struggling to understand why sound does not work very well on my fedora 17 system.

If I run
aplay -D hw:0,0 horse.wav
I get no sound out.

If I run
aplay -D plughw:0,0 horse.wav
it works

If I run Clementine with the Gstreamer audio engine set to
Output plugin = Audio sink (ALSA)
Output device = hw:0,0

That also works.

If I run Totem Movie Player sound does not work.

What exactly is the difference between hw and plughw. When I read the link
http://www.alsa-project.org/main/index.php/Asoundrc
and follow the instructions it basically says that
aplay -D hw:0,0 test.wav should work.
Can anyone help me understand whats stopping it working on my system?

Thanks