WiFi question

[Lolo4321]

Hi,
I have a bit strange question. Why cant you use a Wifi network without internet to make your devices communicate ?
Like if i dont have an internet connection, but i have my own WiFi network why I cant use it to transfer data between two devices?
If i have like a wireless intercom, or even a wireless camera security system that is connected to my WiFi network ( without internet ) why can't the devices communicate ?

[jaxone]

Of course they can , you just need to assign them IP addresses and then you can