What does matching location mean in the below description of tensor.backkward?
backward ( gradient=None ,  retain_graph=None ,  create_graph=False )[SOURCE]
Computes the gradient of current tensor w.r.t. graph leaves.
The graph is differentiated using the chain rule. If the tensor is non-scalar (i.e. its data has more than one element) and requires gradient, the function additionally requires specifying  gradient . It should be a tensor of matching type and location, that contains the gradient of the differentiated function w.r.t.  self .
Kind regards,
Jens