Doubt about Default Material

[Justanother1]

Wavefront Object Material explanation .....
Diffuse is the surface color. Usually where you'll put your texture map.
Ambient is the lighting surrounding your model. For best renders, this should stay fairly dark as this channel affect shadows.
Specular is highlights. This channel can be tweaked to show hard or soft materials, rubber, glass, etc.
Emission is self lighting. Keep this channel black unless your model has self lights, like light bulbs and lamp models.
All these channels can take UV-texture images and each will react different to them. Most external rendering apps will start with these and add more channels like Reflection and Subsurface Scattering.
Wings3d can also use Bump and Normal Maps now (after much whining from ppl like me ) and Opacity can be done with Alpha-png texture images.