Networks Built Inside Other Networks

An overlay network is a hidden virtual layer sitting on top of the physical internet. These systems create custom paths for data that ignore the rigid routing rules of the actual wires and cables underneath.

You use overlay networks constantly without realizing it, as they power secure VPNs and peer-to-peer file sharing. By treating the physical internet like a blank canvas, these networks can connect devices that aren't physically linked at all. They essentially build a private, digital highway over the public infrastructure of the real world. This flexibility is what allows modern global communication to remain both private and incredibly efficient.