Let’s put two Macs MAC1 and MAC2 on the same table. They are connected to the same AirPort (wi-fi) network. They are connected to the access point AP, which is far away, at 10 meters.
The Macs are not in an ad-hoc (computer-to-computer) network.
Now, let’s send a file from MAC1 to MAC2.
Will the communications go until the access point AP and back ? Or will the waves take the short way between MAC1 and MAC2 ?