what is mean black & white texture I download .obj modeling file on the internet
I open the 'texture' file there is a lot of black and white image.
I think black is mean that a part of a model.
Can I select only the black part of UV map or model?
I want to put on a material to the black part.

Thanks!
The map could be a roughness map, metallic, Transmission, and so.
GrayScales give you a value for drive a single parameter. 

Can you post images?