The answer to this depends on the type of device and how it is connected to your hub or the cloud. For zwave and zigbee devices, this is a protocol specific id. For local lan devices this is usually (but not always) an encoding of the network address. For other types of devices it is some unique id that (usually) has some meaning to the app or parent device that manages the device.
The Device Network ID is associated with legacy device handling. Devices that use newer style integrations (identifiable in the IDE by the ‘placeholder’ device type), such as mobile presence in later releases of the mobile app on Android (don’t know about iPhone), do not expose a DNI.
Do you have any idea tho why the location wont work with android?
You can see on the screenshot that the two android phones had their last activity hours ago and the iPhone was the only one to react when I left home.
On SmartThings Developer Tools website I tryed to add a new device (Samsung AR7000 air conditioner) to integrate it later in homeassistant.
what is the “Device Network ID” of my AR7000 air conditioner?