Correct me if I'm wrong because I don't delve into this too often.
It's possible to select and furhter identify whether its a device that connects to the internet (router and modem, or hotspot) or whether its a device like a printer that can connect to your network.
I'm no expert either, but you can also search for Bluetooth items nearby - although the range of such devices is typically 30 feet (10 metres if metric), before they drop off and become out of range.
WiFi can be made to travel quite a bit more - depending on the strength of the device.....I have seen WiFi travel around 109.3 yards (100 metres in metric) :p
That was a high output WiFi transmitter for a rural home.
I am fairly ce3rtain that you can only 'interrogate' known devices as to their properties, type and MAC configuration etc. Unless you have access to the device (electronically with password etc) you may not be able to determine what it is.
A lot of devices can be determined if you are familiar with Network hardware brands, names and models etc.
Sometimes people even change the device name to 'Printer...." etc