The UVW Transform Texture takes an input texture and applies a map to transform the input texture’s UV layout on top of the input texture’s own UV coordinate transformation.
It is applied additionally to the input texture’s UVW transform and this concept becomes more useful when used in conjunction with other mapping textures to combine different scales/orientations/translations of that same texture to create a larger detail range.
The UVW Transform Texture can be used in conjunction with other mapping textures like the Triplanar Map texture, Mix Texture, Cosine Mix Texture or the logical texture maps (Comparison) or arithmetic texture maps (Add, Subtract, Multiply).
Here is an example where there is a need to combine different scales/orientations/translations of the same texture to create a larger detail without creating obvious patterns:
