Network based transfer learning

Could you please elaborate the concept of network-based transfer learning. Is it the same concept that we use for image classification through pret-trained models? Can we call it network-based transfer learning?

It’s explained here: https://link.springer.com/chapter/10.1007/978-3-030-01424-7_27, but I am confused. I need clarification on this concept. It would be a great help.

Thank you!