Please explain how the network part of an openvpn (vpn) server works?

Question

openvpn

I don’t understand exactly how we create a virtual interface and to this interface and for vpn users we create a separate IP address as a client through this virtual interface sees a real local network ?? these are different networks, clients behind nat, or how is there routing between networks or what?

Answer 1

there is routing between networks

This.
If there is no route, then they will not see it.