There are no files or names. All texture files are embedded into the object by default when you apply them.
There is a way to enable "External Texture" in Preferences, but it would take an effect next time you apply a texture to a material and the path/name would be listed below texture maps section.
Personally I would not want that as objects/projects would become dependent on a specific paths/files and if you move/delete files/folders accidentally you may invalidate a lot of assets, specially in a long run.