sunray is right.., additional to that
here net, path and layer are not same.. There is quite difference..
To be more understandable
Net is a connection with common netname [ex:- net1] we used to say it in verilog
wire is a connection with some metal layer [ex:- wire1 but this wire has some metal layer like metal1[copper iron etc..,]]
but both are relevant to each other
path is the way they connected.. its a global thing..
Layer represents metal1 metal2.. etc..,