There are "Transform" in two places. Is there any specific website to explain this in detail?
The one on top is the transform properties of the Shape (Rectangle 1) that is on the Shape Layer (Shape Layer 1). A Shape Layer can have several Shapes and each one has its own transformation properties, while the Shape Layer (container of all the Shapes) will have -as every layer except the audio ones- its transformation properties (those below in your screenshot).
That Transform refers to the transform properties of the Layer, in this case Shape Layer. So, green arrow.