What's the difference between VrayLightMtl and Self-Illumination in a VrayMtl?

V-Ray V-Ray for 3ds Max General
1

What’s the difference between VrayLightMtl and Self-Illumination in a VrayMtl?
Isn’t the same?

Thanks

2

Yes, both shaders have a “Self-Illumination” property, however, they have unique properties as well, which makes them suitable for different purposes.