Lighting model in the Default DAZ Shader does what I said - modifies specular response (which will affect how the surface responds to the HDR environment map) and SSS*. The term may be used in other ways elsewhere but not here. The different shaders are shown in preview, and render, differently of course - if not there would be no need for additional shaders.

• in fact it changes the shader used - we used to have the separate shaders, with different properties showing for each that are largely hidden in the Default Shader in favour of the common properties, available but they have been gone for a while now. The cartoon mode in DS also swaps the shader code on the Default DAZ Shader which is why it affects only surfaces using that shader.