ArOZ Online System that runs on Raspberry Pi Zero W / Pi 3B+ or above require at least two WiFi Adapter to work. But in most of the cases, even two wireless hardware is built in, most people only use one of them at the same time. Hence, switching on of them off will save more power and extend the battery life of the device.

By default, wlan0 is WiFi Client and wlan1 is Acess Point

If you are accessing the ArOZ Online System via Local IP Scanner (e.g. lanips.imuslab.com or ArOZ Portable Scanner Apps), do not shutdown wlan0
If you are accessing the ArOZ Online System via directly connect to the devices' WiFi Hotspot, do not turn of wlan1.

If you don't know anything about WiFi or AP, just leave both of them on.