A 4-port switch is integrated in the access point, which remembers the MAC addresses of the connected devices; as if it were a standalone switch. The WLAN part is like an additional port that is also connected to the switch. Thus, it knows which device is connected to which port and can operate them directly (without a diversion).
If Netgear WAC124 is used as an access point on two floors: identical SSID name with identical password possible. Mobile phone, tablet or notebook automatically select the stronger signal.
However, if you want to know which access point you are connected to, then name: xxxxx plus floor number and password identical on all access points.
|----- Internet (WLan)
------| ----- WLan1
------| ----- WLan2