Gore-Tex fabrics are usually part of a laminate system, often consisting of three layers.
The outer layer is a protective layer, manufactured from a strong robust fabric which is DWR treated. For Gore-Tex Pro garments this layer is even more robust.
The mid layer is the Gore-Tex membrane making the fabric waterproof, windproof and breathable.
There is not always an inner layer in all garments, this is to provide inner protection for the Gore-Tex membrane