[mercora]

P2P here means it will form a mesh network which itself means every node in the network (your clients) tries to connect to each other as "directly" as they determined possible by some routing algorithm. This is in contrast to a a hub and spoke model for example, where every node will connect to a central hub and communication between nodes need to pass through that hub.

[Black101]

I guess that would be most useful if you don't have any reliable 24/7 internet connection to install a PiVPN server on...

[mercora]

while that would partially help, i think there are better use cases for this type of setup. it is less about discovering endpoint addresses of peers (you could setup a statically configured mesh network too) and more about moving packets efficiently between peers. it can reduce load, latency and bandwidth requirements all while being more resilient to outages... a full mesh network should still work after any other node/peer fails, making only itself unreachable to others. a mesh network could even be able to reroute packets avoiding the failing paths if possible at all. for example your phone could be connected to your home network and your mobile ISP network, so when your home network loses internet connection peers could still route traffic through your phones mobile isp network to other peers in your home network. if you use your VPN to connect home from abroad it is pretty useless though. a mesh network between two computers makes no sense and probably should not be called like that. However, just connecting few sites and some road warriors makes this option quite attractive already.