What is the difference between ddf and dds files?

Where should they be located?

How do you open them?

i don't know for ddf

but i know for DDS ;)

To open it with photoshop use this plug in from Nvidia

http://developer.nvidia.com/object/photoshop_dds_plugins.html

I can't find the dds files????????????????? I know they are there!!!

check here by exemple:

\Assets\Art\interface