How to use defuse maps?

Defuse maps are the black/white images right? Two questions:

What do they do?
How do I use one?

Thx :smiley:

Diffuse is just your standard colour map. Nothing special about it.

As far as I know, blender doesn’t support diffuse maps, it’s just one color, whatever color your mesh is (that is what someone told me, so if your object has stripes, make it different colors according to what your texture is. Example since I’m bad at explaining things:

The first is the rendered image, the second is the image in blender, you can see I’ve applied different colors to the regions where the color is different. Does that make sense? That is what someone told me to do…